Definitely try it before you buy it.
I've had 3 of JP's guitars and sold all of them:
JP6 Koa (6 String)
JP XI Onyx (6 String)
JP Majesty Monarchy (7 String)
Of the 3, I can offer the following first-hand experience in comparison to each other...
JP6 Koa:
+ Had the best clean sound, and coupled with the piezo was amazing
+ Easily had the best sustain overall
- Was horribly susceptible to humidity changes and had fret sprout up both sides of the neck (may have been due to the fact that Guitar Center kept in in a glass case along an outside wall for God knows how long)
- Metal tone was kind of meh
JP XI:
+ Seemed to hold it's tuning the best
+ Had the best metal tone, very clear yet sustaining
+ Clean sound was decent, though not as nice as the Koa
+ 20" super flat neck radius - smooth for leads
+ Whammy bar seemed to stay in tune the most
- Came with .009's on it, and when I put .010s on it was a ***** trying to get that bridge to level off correctly
- Body was a bit off in size to me, kind of like an oversized Strat version and didn't feel quite right
- Was very difficult to intonate. I asked on the EBMM forums if it was just me, and some guy on there said he had FIVE JP guitars that all did the same thing
JP Majesty Monarchy:
+ Superior fit and finish
+ Very comfortable body (a bit smaller than your average guitar)
+ Super easy to get to the higher frets, even with my big hands
+ Very powerful and sustaining metal tones
+/- The tiny recessed pickup switches took a lot of getting used to, though I will say that having them in a "sweeping arm" motion per JP's specs did make a lot of sense
- Had a surprisingly CRAPPY clean tone, even with brand new batteries, high quality cable, and straight into a Mark V
- I could not get used to that 7th string to save my life - it just got in the way and threw off my visualizations of scales, etc.
Moral of the story: What works for your musical hero probably will not work for you. They just weren't for me I guess.
I've been tempted to try one of the newer models, but it's kind of a 3 strikes deal for me at this point, so I'm done.