Weight is not the only issue that comes into play, though, as aerodynamics and other flight characteristics will be a factor. For example, I much prefer the old 737-200s to the next generation 737-600s (which are close in size and weight) as the newer planes smooth out the bumps and the older ones seem to ride them like the plane is a brick. Of course, a Beech 1900 versus an A330 is no contest!

I was in an E 190 last winter on a very bumpy ride into Calgary and found it to be quite decent. It is hard to do head to head comparisons as of course one does not have the opportunity to be in different aircraft in the same conditions. I am no fan of the A320 in turbulence, and yet in the CRJ I am hunky dory (and I have a lot of flights in the RJ so have been in varying conditions).

In any case, I would choose the E190 over the A320 as I think general comfort is greater and will do more to negate the psychological effects of turbulence, if not the physical ones.