I tend to size down , I'm 5'11" and technically for the bikes I ride I should be on a large but ride a medium , I'm now on no 3 Cotic , I ran a med 26" Soul , then a med 27.5 Soul , when looking to try a full bouncer I managed to get a few test rides in on both med and large (flare and rocket) and though the large should have been the right size it felt like a gate , my current steed of choice in a med Rocket (pre long shot so old by modern terms at 2017). Couldn't believe how much grip you get from a modern full bouncer when climbing compared to HT and going down is something else , the main reason for the bouncy bike is my ever raging body , I can do the same ride on the Rocket as I did on the Soul but need less wine and ibuprofen when I get home .
Ah ha! Just to totally confuse the issue, I am 5-7 and on a medium duckegg blue Soul late 26, a 2010 Ragley Mmmbop LARGE, a 2019 Sentinel medium...yep...I size up....and like the huge stability downhill which I get. But I do run in line posts and 35mm stems.....
That shouldn't make you feel sad. I love tearing down a good rock garden on my modern full suss, but when I ride my retro's they do feel very different and odd, with the elbow's out ,head down position. But I feel 21 again and you can't beat that feeling. Modern and Retro are worlds apart and I wouldn't have it any other way
Vive La Differance :!: