Brushless - I had a B4 and I went to brushless first. A 7.5 or even slower is plenty power and with brushless you get more run-time the way it is. Good point about the weight. Most cars on the market are designed for the weight of a NIMH pack. If you have decent nimh packs, start with brushless. This eliminates all loss of motor power from poor brushes and worn coms and saves you money so you can save for lipo later on. That is what I did.