6’4″ with 35″ inseam and a 2017 Fuel 29er 21.5. I was tempted by the 23″ but there is a real jump between the 21.5 and 23 for some reason, the seatube goes from 510 to 560 I think, I wouldn’t have been able to run my 170 reverb on the 23. With your inseam I’d get the 23 though. Looks a bit of a gate but fit is what counts. Also worth pointing out that there is a big difference in headtube length and stack between them, I have 20mm of spacers and 40mm rise bars to get the bars where I want them.
Other than that can’t recommend it highly enough. Had a carbon XL Stumpy evo and the alloy Trek is superior everywhere
Edit; just measured 790mm BB to saddle rail. Would think BB to top of saddle would be more accurate though?