I've used Trakpower as well as the Orion 4800 and the Orion 3200 Carbon. I found the Trakpower to operate the best out of the lot, but there wasn't a lot between the Orion 4800 and the Trackpower. I felt that the Orion 3200 Carbon was the worst. Was simply lighter, but in a sanctioned event you must add more weight to the car, which means that you just have a pack with less runtime.
All parts fitted in fine with the Cyclone and the extra size of the 4800 Orion and 4900 Trackpower made it a more snug fit in the Cyclone which I preferred also. :-)