None, it can't be compared to anything except the Q loader, which has way too many drawbacks to even be considered
Marker Setup:
WGP Orracle w/ White Delrin Jam Bolt, Kapp Detent, Kapp Beaver tail, Kapp Cocking Rod, Low Riding Reg, Dye Pressure Gauge
Egg II w/ Warp
47/3000 Crossfire Tank
Strengths:
Moves your hopper away from the top (duh), feeds very quickly
Weaknesses:
Kinda side heavy (you are a pansy if you care tho)
Review:
Wow, I just got back from playing my first day with a warp and all I can say is Awesome! A warped cocker is the sweetest thing I'll ever shoot. I did a couple custom mods to bring the weight down (I connected the batteries from the warp to the egg, so I can put batteries in either and it works for both) and to make the warp shoot on every trigger pull (custom switch job for my orracle). I was shooting what I believed to be better players right off the bat, they didn't see me coming since my hopper wasn't sitting half way out of the bunker. Instead of seeing a hopper to aim at, they saw paint flying at them. Very, very fun! Even my DAD saw the advantages to a warp feed, and is considering getting one. These things rule, I can't say enough good stuff about them. Good construction (although the battery connector has been known to break, I resoldered all of the connections when I did the 12v and the battery connection mod) and great idea. I'm just surprised more people don't use these!
Conclusion:
Just get one! It probably helps to get one while you are still getting into paintball, as you don't have any habits to break from the old hopper style.