Alesis makes a good fx unit, I used to have one of those cheap Ineko's and I loved that thing (will probably buy one again when I have some cash). Don't know anything about the Behringer, but that Alesis should probably do you well. From what I remember on that Ineko I had the sound quality was really good...

i think the air uses ,like an infrared beam to change the effect parameters,(like delay, pan ,yadda-yadda)probably piss easy to use  ...and the other looks like a tweak machine ,ie. two hands on knobs....

~both have the same quality...but totally different in the way they're used