The Daryl's idler system is better in the long run, as it's spring loaded. If your tracks eat a stone or piece of wood, they will give and not breack the track or TU. And in the beginning running the stock plastic tracks, take the pins out and put them back in from the outside. They will tend to walk out, and inserted from the outside they will not catch on the tank body and break the tracks.

With the TU's, you will need the Schumo geardown no matter what system you buy. The stock Type 3 Tamiyas will hold up for "Sunday driving", but if ever you get in to competitions, you will need the ETO HD system. The HD system comes with a final drive reinforcement made from machined aluminium, and it also has a bolt on truss to join the TUs together for more stability. Using them and the Daryls Parts trans brace, you will have a rock solid KT hull, which tends to keep your tracks on quite well. Graupner Speed 400 motors will also be a good investment, as are the low resistance electrical plugs for motors and batteries. Resistance is your enemy, and the plugs significantly reduce same.