Someone else may have a better way, but for me, when I'm going back and forth between Avid and AfterEffects (or FCP and AfterEffects), I've had best results in exporting uncompressed (i.e. compression= "none") quicktimes. This does result in huge file sizes, but it's the only way I've found to avoid the gamma shifting that occurs when bringing material through the different programs.
you'll be able to "fast import using the proper codec. While the animation codec is generic and is always good to fall back on from machine to machine, you'll save alot of time just using the meridien uncompressed codec.