FWIW I'm 6'2" with a long inseam and big wheels work a treat for me, anyone taller than that I recommend throwing a leg over a decent example to form your own opinion. I ride a 29er full sus as my main modern ride and it really works for XC, results speak volumes. Plus I've built a steel rigid 29er Singular SingleSpeed with lots of retro appeal for fun.
That said, I'm keep riding my 26" retro steeds with pleasure plus the modern 6" full sus "ride it up and off everything" trailbike. But 29er options for the latter are popping up now and I probably will try one at some point in time.
Oddly I never warmed up to mixed wheel bikes, neither 24/26 nor 26/29.
Enjoy!!