Yep, those are the drawbacks. But if you stick with low res/low colour you should be good.
Anyways, Chris has added a few things to help with the speed. You can now split the game up into resource files instead of compiling it all into one giant exe, but it can still be slow.
Apart from that he's currently working on a windows version so that'll help, but it's a few months off at least.
Rode
Oh, and I wouldn't brush AGS off as 'cheap' so fast. Some of the games are quite amazing, and if you can get past the speed issues you can do almost anything with it, and for guys like me who are too dumb to figure out AGI studio, it's really great. (One day, one day...)
Try a game called 'Pleughburgh' (That's probably spelled wrong), it's really well done.