I've been playing this game through steam and been enjoying it, unlocked most of the classes and got a few charactors to level 20. Slayed Onyx a few times. Even managed to almost get my priest's fame bar to max before he died from lag
I am finding the game a bit boring when do you do reach level 20, doesn't seem to be much to do except grind fame/stats. Might stop playing it after I've unlocked all the classes.
As for the whole micro-purchase mechanics I fail to see why anyone would spend the money. As far as I can tell it's only for the charactor you bought the items for and if they die you also lose them.
Equiptment comes easily enough so I don't see why you'd need the extra bank space. I suppose the extra slot might be good if you get bored of a class or you need a healer/nuker for a god, although the game seems to have a bias for quanity rather than tactics.
Over all a good little time waster which I might pop in for a couple of minutes or so, but lacks any real "end game" content.
EDIT: One reason not to use the steam client is that the game overlay still works in the game meaning if you get a spam of messagers you won't be able to see your inventory and/or health potions. Goodbye level 19 Warrior.