My personal opinion, I rate the two trucks pretty much even on the track. I've run the RT5 since it's release, and have switched to running the T4.1 over the last few races for a couple of reasons; but the biggest by far is parts availability. I'm not hard on equipment by any means, and I break very little but it's been challenging to get even small parts on some occasions, and the chances of picking something up in a hobby shop (at least near me) are non-existent.

A couple things to consider on the RT5 - the ballstuds and cups are larger and they hold up very well.. that said, good luck finding a replacement somewhere in a pinch. And the alum rear hubs are considered a required upgrade by most, which is going to add another 40 to your buy in cost.

On the positive side, the quick change hubs / wheels all around is a very nice feature, and the shocks are great. The new AE v2s are nice and all, but I still find the Kyosho shocks to be best in class..

With the T4.1, build it with better ballcups and you're pretty much ready to roll. For me, I don't want to carry an entire kit worth of parts around all the time, and I felt I had to do that with the RT5, where with the AE my odds of getting something trackside (even if its from another racer) are far better. The last thing I want to do is travel a few hours for a race and get hosed by a 3 dollar part

Feel free to drop me a PM if I can help with anything else.