The scripting language in AGS is a very cute and simple one, so I guess that's a plus. However, Chris Jones who is the maker of AGS, has cut a few corners when it comes to usability: there is no "new room"-feature, and you can quite easily overwrite your rooms by mistake. When creating a "blank" game in AGS, the engine by default adds a bundle of default sprites (horrible ones, too), as well as a default character, etc., all of which can't be deleted. The reason is so newbies don't accidentally mess up their game beyond repair, but to me, it is merely a source of frustration. Still, if you can live with those little quirks, AGS is an easy tool for creating point-and-click adventures.
If you want to create point-and-click adventures with the retro look and feel of Monkey Island I & II, or text parser based systems like Leisure Suit Larry I, AGS already has the corresponding GUI's. There is something to be said for that.
And, yes, it is both stable and robust.
With that said, I still like WME better after only seeing 5 minutes worth of it, and I'm a HUGE Monkey Island fan. But that WME interface is just SOOO beautiful! Great Job Mnemonic!
But I guess the real question is: Once the first real (ie. big) games using WME come out, how smoothly will they run, and how flexible is the dialogue scripting when a game designer wants to create huge chunks of dialogue quickly?
The important issues to me are: Flexibility, speed, reliability, and how well the engine will suit my game design process from a usability point of view.
Scarpia