RE: Thunder tiger ST-1
Other than the carbon fiber, my ST-1 is the pro kit. I have all the red aluminum upgrades: front/rear braces, steering ackermen, upper brace and aluminum clutch shoes. I also have the optional TTR shock springs. You can get them all from amainhobbies. All the upgrades were about $100 total. (e-mail RGX he may be able to get the parts cheaper) I put in an Axial .28 with the dynamite 007 high torque pipe. (also the TTR pro .28 w/3 chamber low end pipe). They are excellent engines for my skills. I am a "SPERT" driver. (combination of sportsman/expert). Even though I have some upgrades, the stock truck is still a good vehicle.
I driven the CRT and Mugen truggies and the ST-1 holds up fine. They all have their strong and weak points, but pretty much the same. It really boils down to set up and the driver. I know some guys at our track that can drive anything and make it look good. I am a fan of RC so I like them all. I like to see a variety of trucks at the track. To be honest, there are a lot of awesome truggies on the market and in the right hands they will all look like champions.
If I had a $1000 to blow, I would get a 1/5 scale offroad. That HPI Baja 5b is NASTY!!! A guy brought one out to our track and it was awesome. The only bad thing is that you need about 4 or 5 people to buy one also or you will be playing by yourself.