The slash 4x4 is great! Upgrade the center diff bearing with a higher quality bearing. The Tekno rear cvd's so far have been great, so it looks like those will solve the rear axle issue. If you buy it new with a clear body, you can sell it on ebay for about the same cost as a more durable JC or proline lid so it won't cost much to upgrade. After that, you'll want to start replacing the bearings...the stock traxxas ones have a bit to be desired in longevity. Overall, my slash 4x4 has been the most durable truck I've ever raced and is great on the track with a little tuning!!