Pug makes some very good points, and it's certainly not for everyone, but I have been VERY comfortable in mine.
My dive buddy and I have dived our AGA's almost exclusively the last few years (I only dive without it now when I don't dive with him). We do dive them with the Buddy Phone. Air consumption does go up quite a bit when you initially start using the mask, but I found that once I had a few dives on it and became more comfortable using it my air consumption returned to very near normal. The out of air issues can be a concern. I almost always bring a spare mask in a pocket. I wouldn't reccomend it for cave diving, or even tech wreck diving. It's just to involved. You can buy a "block" assembly to pipe in at least 1 more gas supply. You can see one of them at
www.sarind.com (RSV-1). The mask does make cold water diving more comfortable. I haven't found it a pain to clean or don, but I have also been servicing my own gear for many, many years.
Like I said, it's not for everyone. I do find it A LOT of fun to dive with, and that's what diving is all about for me: having fun. It's a serious investment if you don't end up enjoying it, so I always suggest diving one before you buy (which is fine for friends, I have 2). The best deals I have seen are "show" deals at DEMA. You can usually cut a pretty good price there (they just won't show up for a few months). Since you've already tried it, and liked it, you are probably not going to stop liking it any time soon. Go get one. If you want to sell it later they hold their value reasonably well.
I will add one more comment, do not get the positive pressure version unless you are diving with it in contaminated water and are using a surface air supply. Air consumption will always be above normal in those models. Get the demand only model, it's also slightly cheaper then the positive pressure version (I think).
Let me know if you have any other questions.
Tom