the TRS has an extruded base so it wont be as fast but you will be able to skip a day or too on wax. It will be a little softer than a T.Rice so it will be able to kill it in the park a little. Will handle kickers, pow, and groomers.
The T.Rice just goes big. Sintered base is super fast, you will need to keep up on waxing though. A little stiffer than the TRS so it can handle big kickers and will go as fast as your willing to go and handle it with ease. The board is made to go huge and kill it in powder.
I personally ride Last years Trice with BTX and the Trice from 2006 with just MTX.
Altered genetics is sick, has a sweet combo wood core, but is more directional, where the TRS and Trice are more twin shape. Nicest, highest quality board Gnu makes, I would stay away unless you know you want it.
You will have way more fun with a TRS, a T.Rice would be more than you need, and the Altered Genetics wouldnt be as fun.