[RC-Monster Mike]

I use esc brakes on my stuff. Makes for an easy conversion. The CR buggy mount is ideal for use of the smaller spur gear - the mounts are otherwise compatible(same servo tray, and same hole pattern, so only the height of the mounts are different between the crt and CR mounts).
I can comfortably finish a 15 minute race on my race truggy using a Neu 1515/2.5dmotor on 5s 5000mah PQ or FP packs. My truggy weighs in at about 10 pounds even with this setup. A 30 minute race will require either a battery swap(using a similar setup as mine), or a LOT of battery, which will weigh the truck down a bit. The A123 cells are less powerful and heavier vs. a similarly powered Lipo, but if you have a couple packs and can perform a reasonably quick battery swap, they certainly will work just fine and they are a nice, safe, quick charging chemistry.
The CRT and CR mount can be positioned at the front left corner of the truck as well, which allows room for 2 battery packs behind the center diff on the chassis. swapping two packs will clearly take longer than a single pack swap of course. I use a single pack on my vehicles, but there are plenty of folks who use the dual pack strategy as well - to each his own. :)