The differences are going to be really subtle and I doubt you'd actually feel or be able to measure them but the TT set has matched slightly deeper rims and they claim the front hub is more aero. That might make a tiny difference to CdA if you're riding long tri's but most folks are running far more aero gear even for ironman distances and definitely for short time trials. The extra couple of spokes in the aero wheelset likely translates to a slightly more robust wheelset but that's probably offset at least a bit by the deeper front rim as deep rims are pretty strong and don't need as many spokes to stay true.
Basically these wheels are very similar so are you more concerned with the 30 grams or so difference in weight or do you want a slightly more aero wheelset or is the price difference enough to help you decide. Either way they're both really nice clincher wheelsets, hard to go wrong with either one.
It seems to me Easton has a few too many similar wheelsets in that line and your question is probably being asked by a lot of folks confused over the lack of product differentiation. I wouldn't be surprised if one or the other doesn't show up in next year's lineup.
Thank you so much Dude. That's what's I needed. I'm actually going to be road racing on them. That's why I had the question. They look very similar. I bought a set of the TT, tubulars because the aeros were not available. I guess the worry I had was in regards to stiffness out of the saddle. I know the lower spoke count is going to offer a lack of stiffness in the TT but I think the difference is going to be so minor I won't be able to detect it.