I believe the larger Neil Pryde masts , ( 490 and above ) are constant curve not flex top as everyone believes , could this be true ?
Normally i think matching masts to sails is very important.
The reason i say this is , when i rig my larger ( 2009 -2012 ) North Sails , Rams and Warps ( which use constant curve , and dont recommend NP masts ) they seem to set the same or better on NeilPryde masts. I have both masts to choose from ( x6 , platinum ).The cams rotate better on the NP . Both masts use the same downhaul and outhaul settings , this is also what makes me think they are almost the same. On the water im tipping i prefer the NeilPryde , ( also i am 115kg so mabee this has something to do with it , but then i would think stiffer is better for heavier ). On smaller sizes , 430 and under i find they are waaaaay different and a NP wont come close to working.
Am i missing something and kidding myself preferring NP masts ?
I read in a mag an interview of the pryde designer who was saying that only the small sizes NP masts were flex top to give the same profile as a longer CC.
He said that you needed the short mast to flex more because of it's small length a short CC wouldn't bend enough.
So you're probably spot on with your deduction ! 
When I brought my X 6 .pryde .460 .i googled it and it said..... to my surprise ,will work on most sails? 90% carbon .
i use mine on a x15 tushingham .but looking at the mast bend it defiantly looks like a constant curve .if it works your on a winner.Imax1...but yes I agree with you .
its a bloody good mast .
based on Peterman's analysis:
www.peterman.dk/windsurf-NP-X6-mast-study-780gb.htm
the shorter masts are around 19 in terms of flex bend
the longer masts are closer to 15
so, yes, the longer ones are closer to CC/constant curve
and work better than say a hard top mast (which seem to be disappearing) on a CC sail
I have tried a MauiSails mast and a NP mast in my SW Retro 8-oh
of the two, the NP looked better and I prefer it over the MS on this sail
with the NP felt the leech was a bit loose, but it was only on up high
(and yes, I have used this sail in the winter on ice in 10 kph winds)
Hang on. I've been told before that mast choice is less important in smaller sails. Who to believe?
i thought you did a little bit, but suddenly the movie went private
hmmmm
i still believe longer NP masts are "tending more towards CC", but NOT really there yet
What's going on , is there a conspirency ? Men in black stuff going on . I'll shut up if NP or North give me a quiver and plead insanity !
They say imitation is the sincerest form of flattery.
Thank you Neil Pryde. You have copied my innovation of the downhaul line pocket I asked for for at KA Sails Australia, and which we implemented on the KA Koncept quite a few years ago. I am suitably flattered! 
BTW, I have in the shed a NP 430 100% mast, which was left in my care by my Japanese friend Hajime, which is actually LABELED 'Constant Curve' (and I tested to confirm it).
It works very well indeed on my 2016 7m KA Koncept. 
Select to expand quotesailquik said..
They say imitation is the sincerest form of flattery.
Thank you Neil Pryde. You have copied my innovation of the downhaul line pocket I asked for for at KA Sails Australia, and which we implemented on the KA Koncept quite a few years ago. I am suitably flattered!
Are you serious, North Sails have had a downhaul line pocket for at least 12 years as have many other sail brands. 
Select to expand quoteAUS4 said..sailquik said..
They say imitation is the sincerest form of flattery.
Thank you Neil Pryde. You have copied my innovation of the downhaul line pocket I asked for for at KA Sails Australia, and which we implemented on the KA Koncept quite a few years ago. I am suitably flattered!
Are you serious, North Sails have had a downhaul line pocket for at least 12 years as have many other sail brands.
Yep. I never saw them or heard of them.
Must be parallel genius!
Select to expand quoteAUS4 said..sailquik said..
They say imitation is the sincerest form of flattery.
Thank you Neil Pryde. You have copied my innovation of the downhaul line pocket I asked for for at KA Sails Australia, and which we implemented on the KA Koncept quite a few years ago. I am suitably flattered!
Are you serious, North Sails have had a downhaul line pocket for at least 12 years as have many other sail brands.
Forgive him he is quite old lol
Select to expand quotejoe windsurf said..
based on Peterman's analysis:
www.peterman.dk/windsurf-NP-X6-mast-study-780gb.htm
the shorter masts are around 19 in terms of flex bend
the longer masts are closer to 15
so, yes, the longer ones are closer to CC/constant curve
and work better than say a hard top mast (which seem to be disappearing) on a CC sail
I have tried a MauiSails mast and a NP mast in my SW Retro 8-oh
of the two, the NP looked better and I prefer it over the MS on this sail
with the NP felt the leech was a bit loose, but it was only on up high
(and yes, I have used this sail in the winter on ice in 10 kph winds)
What's that white stuff on the ground?
(from the unifiber news letter ...again)
HOW DO UNIFIBER MEASURE MASTS FOR THEIR SELECTOR MATRIX?
The Unifiber Mast Selector chart is composed based on varying sources of data. Of course we have a measuring machine at our base, but we also track data from external sources such as magazines, sail designers and riders, plus, at Unifiber HQ we frequently visit customers and collect multi-brand mast data too. AVERAGES Mostly we take multiple C100 masts as the reference of various brands as, in general, those represent the most accurate bend curve for those sails, which are designed to perform best on those C100 masts. We also found quite big differences in tolerances regarding production with all brands.
Fluctuations of bend curves and stiffness from +/- 1-2 points (bend curve) prove that none of the brands are 100% consistent. So we measure several masts per brand and take the average of those measurements into account when constructing the Mast Selector Matrix Tool.
SETTLED SITUATION
In general brands don't have much interest in renewing bend curves year-on-year since compatability issues will arise across sail/mast combinations from previous seasons that will cause conflict for their regular customers. We follow the market based on feedback we gather as well rumors we pick-up on upcoming changes. (Some of those are due to happen soon.) When there are strong signals we will investigate deeper by sourcing product in the market and take measurements and update our mast selector using version numbers. In general, to obtain correct data, ideally we would like to measure 3 of the same type of masts (since each brand face inconsistencies in production, to have an average result) although for practical reasons this is not always possible.
SPANNING THE SPECTRUM
We use 3 dots to mark the bendcurve of different brands to help clarify which bend curve is more preferable in marginal situations where one brand's bend curve is close to another category of curve. We show 5 blocks representing the same curve color simply because all brands, including our own, will face prodution tolerances during production. These variances are simply unavoidable and any manufacture telling you that they do not have a range of tolerances is not telling the truth. In general these tolerance are acceptable in terms of performance, although specific brands want to claim differently.
PLEASE MOST OF THE PEOPLE MOST OF THE TIME
According to our knowledge, we feel about 90-95% of customers who purchased Unifiber masts are happy with the performance of their sails and have bought a product with a sensible average of curve characteristics to use on a range of sail brands they may buy in the coming seasons.
Additionally, windsurfers who compete or are heavily into sail tuning have options to tube their sails for specific conditions, e.g., for speed sails, in general a Flex Top mast for a Constant-Curve design sail can work beneficially in terms of performance.
