I've been jumping between Adobe AIR & Titanium, and while there almost everything is better (for me) in AIR to target all Mobiles & Desktop, Titanium apps has the advantage of loading faster (initial load).

This is the only thing I have noticed between the two, AIR now at 3.4 is much more mature as a platform, but Titanium loads faster on startup, then they are pretty much on par on performance.