Hey Krisb,
I started with the GGTS and AVS. Because of them, I pretty much dropped everything else. Then, enter the Darwin. I've got a GGT, and 2 GGTS's and the AVS. The GG's are now backups to the Darwin, but I still occasionally use the AVS. As much as I love my AVS, I've gotta say that the flavor from the MAP is better, so that's my primary vape toy, I reconnect the AVS from time to time, but I find myself going back to the MAP tank.
I've also got the stormy tank (or what ever it's called) and some clearomizers that also use the CE2 atty, but even still, the MAP tank is different. I don't know why, but the flavor seems better. There is a way to connect the CE2 to the AVS, Imeo did a video on it but I haven't tried it yet. I have to give it a try some day.
When I fill the MAP tank, it's great until it hits about half full, then I have to tilt it almost upside down for a second or two to force the coil to get wet, otherwise, it's a little dry. This is only because I'm a heavy vapor and mostly seem to vape every other breath. If you let is sit longer, it's fine. The CE2's don't wick as well as the AVS feeds liquid if you vape that heavily, and the flavor is definately different, again, not sure why. I have one MAP tank and just ordered a second because of the flavor difference. Imeo has the AVS V3 coming out soon that has a control ring to control air-flow, just like the current version, but also a way to control the volume of juice flow. I think I'm going to have to get this one too. Call it loyality, but I'm looking for something to make me want to go back to the AVS. The CE2 ohm's that I use are 3.0 - 3.2. Using the GG gear, I was always a HV (7.2 to 7.4V) vapor, so using the higher resistance CE2's seemed to make sense. Plus, with higher resistance, I think you have more options, especially with the Darwin.
Anyway, hope all this helps.
-George