I just went through the same, so I dont know much about the technical aspects, but I can help you from a newbie point of view...

I went with the LST, and here's some reasons why:

I wanted 1/8 first of all. I like the looks of the Revo a lot, it looks like a really well rounded truck, but still, I wanted a 1/8.

My decision was now between the Genesis, Nemesis, LST, and LSTII.

Next, Im not going to be doing any serious racing, and functionality is important, and from what I understand, the Nemesis, and LSTII dont have reverse.

So now I was down to the Genesis, and the LST.

I really was leaning towards a Genesis. The 5hp sounds inviting, and in the RCU video, it looks like everytime the operator hits the throttle, the thing wants to pull the front wheels.[X(]

But then I read some reviews of the LST. It appeared to be very well rounded, the motor is smaller, but appears to be a real solid performer, and the truck weighs like 4 pounds less.

That, coupled with the Hi/Lo range tranny, really made it look good.

Im still thinking I should have went with the Genesis, but who knows.

Another thing is go see what your LHS stocks. I didnt think that would be a big deal, until I started needing to buy stuff.

Good luck, youve come to the right spot for info, this site is excellent!