My opinion is the same as NEXX/replicant's on this. I travel on both, and have no particular preference. If anything, the Airbus models tend to be newer.
I've noticed the trend to Airbus lately, with easyJet now operating A319 in addition to its fleet of B737. Why is this happening? Is there some reason why fleet operators prefer the fly-by-wire planes? Just asking, as I'd be interested to find out.