I found this out the hard way, as most are apt to do. And I think it's a pity that theme developers don't seem to be aware, or perhaps don't give a damn about it. For instance, I like some of the premium themes out there, like Elegant, Woo, and such, but for a while, it was tedious to just switch between their own premium themes. And when creators rely too much on manipulation in code rather than rely on WP basics, that's a recipe for disaster. To wit, the TimThumb debacle. How many themes are now dysfunctional because of that one. I would always recommend the best graphics, wrapped around the simplest theme.

Thanks to Konstantin for bringing up something it seems we've all been thinking about. Perhaps with the exposure of the Tavern, more will take notice.