My 2p's worth from loaders I have owned..
Reloader B (std) - Pretty good although the sound board sometimes fails to pick up a shot if not sound calibrated correctly.
Magna (with virtue crown)- Better, Like the low profile and nice larg capacity. As with the Reloader B, the on/off button is little fiddly and you have to watch the LED's carefully to turn it on/off.
Vlocity (with Hyperdrive chip for better battery life) - IMO the best loader I have tried so far. Simple but effective on/off toggle switch. Force fed rather than sound activated, which I now prefer (A. No sound calibration required, B. You can hear that you are low/out of paint by the whirring sound it makes when it's trying to feed paint). Had a full tourney day with it, no jams issues so far.
All 3 a bit of pain to strip/clean rebuild though (need screw driver). The new Prophecy loader looks like a good one if you can get it. Very easy to strip (no screw driver needed), simple on/off switch.