Erm, not to join a flame bandwagon, but have you tried out any of the other products? Many of them offer whole scenarios, and SE:IVG lets you play enough turns to get a good feel for what the engine can do. With RuneSword, you can even download the entire RuneSword 1 engine and play it for free, in all its(buggy) glory!
I think that Shrapnel's demos are pretty fair representations of their products. I guess what I keep hearing when you emphasize "thorough" is that you'd like the whole sandwich, for 30 days.
That's not in anybody's interest- if I read your post right, then if everybody handed out a fully-functional, but time-expiring game, you'd have a free game every month, instead of buying one
That means that the devs who made the game wouldn't get paid. And that's bad, because most of Shrapnel's devs aren't getting rich and like to eat
If you're really that interested in thoroughness, then you should probably visit the 'Boards here and visit with other owners of the software. See if they're impressed. Shrapnel's 'Boards are some of the nicest around- people are
unusually polite and informative- and you'd probably find out more than you ever wanted to about whatever features you didn't glimpse during the demo