The good news about the Tamiya Spec is that by being a universal specification, it imposes the same limitations on everyone the same, so if you hit your opponent he will be just as crippled as you! (Assuming similar gearboxes, etc)
You can read many discussions of this very issue in other forums. Heavy tanks with low max speed make for poor battle tanks. For those with models whose primary purpose is IR battle, the builder is usually careful not to use a very high ratio gearbox, as Jürgen says. It will also help to increase your battery voltage, for example use a 2S lipo instead of the standard 7.2v NiMH (or upgrade to a 7-cell NiMH at 8.4 volts).
With regards to the TCB specifically, you should turn off any acceleration constraint (inertia) because it will make the sluggish driving even worse. You can set up dual drive profiles if you want, one with inertia and the other without, which will allow you to turn it off after you receive your first hit.