Regards the sprong, you can make your own which works just as well:
http://www.rc-monster.com/forum/show...99&postcount=3
The newer style emaxx/erevo slipper is pretty good, but it can be improved by replacing the stock pads with the aluminum ones found in upgrade/repair kits, or you can even go the whole hog and get an aftermarket slipper which uses 6 pads instead of 3...
http://www.hot-racing.com/index.cgi?...=TRX15HS;c=480
&
http://www.hot-racing.com/index.cgi?...=TRX15GP;c=526