Well the funny thing is despite owning an RWS 45 in both calibres for about 12 years (they look like twins in the gun rack), I've never shot them together in one session. My .22 is a bit more pokey than the .177, but as you say their firing characteristics are from memory very similar. And accuracy is a common denominator between them. In.my case both are converted over to synthetic heads but I will park that one up right there.
I've recently been testing a 45 jubilee that is remarkably consistent and proving many of my prejudices of leather heads wrong.
Definitely one of the classics of the 70s/80s.
Dave