you guys finding the bigger wheels are easier on the back
Hmmm... I don't have chronic back problems but I drink a lot (hard to stay hydrated) and I ride rhythm style jumps where there is a lot of pumping and g-outs so my core gets worked.
I have noticed that I can ride 3 to 5 times a week an hour to two hours on my holmes 22... whereas my 20" steadfast I could do the same for about 6 weeks and then I had to go for massotherapy on my lower back or I was out for a couple weeks.
I think the difference is the fact I have a very upright stance on the holmes... It has a long cs (end of the drop out) therefore I can run a profile push and hoder (really big) bars. My stance is way more upright and the bike still feels balanced not too easy to pull up.
Now as far as riding a rigid bike that is jarring when you case hard the 22 wheel does pop out of hang ups and cases better but it is not hat much better than a 20". In reference a 24" or 26" wheels is worlds away from how jarring 20 ans 22 wheels are. The 22 is better but not by a lot.