Hello Mark,
I’m 6,3 ft tall too and i had exactly the same questions than yours.
I already had a look at the meta V4 in XL size that looks interesting for us, tall riders, but when i saw the pics of an XL one, i’ve found it very ugly. Top tube is note aligned with the rear triangle (It’s nicely aligned on the M sized), damper is inclined downwardly, et seat tube is horribly long… My point of view is that this frame has not been well thought for Large sizes. S & M are really nice, L not too bad, but XL…
Look at this pic : http://fstatic3.mtb-news.de/f3/17/1753/1753943-o5k1qjg3w0ae-image-original.jpg
I finally choose The strive CF 8 race in L size. The things that decided me are of course the geometry, and a test of vital MTB in which they says that L race is a good size for 6ft plus riders : http://www.vitalmtb.com/product/guide/Bikes,3/Canyon/Strive-CF-9-0-Race,15045
The two pilots of the test are also 6,3ft et 6,8ft tall ! And it seemed to be ok for them.
Th only disadvantage is that the seat post tube will be a bit high, but for me, all the rest of the bike, equipment included, is more than nice.
I ordered mine 3 weeks ago and i will receive it on week 14. I’ve just had a look at canyon’s website, and today, the availability of the L size is week 13 !!! So maybe i’ll get it in only 2 weeks !
Let me know what you finally choose, it’s not usual to have the advice of other very tall riders.
Cheers from France.
Nico.