That's a mixed bag, for me. I like the Dresden Doll's demo version of "Girl Anachronism" far better than the studio version on their eponymous first album, but that's primarily because of an effect of overlapping and conflicting voices that was later changed, and perhaps because it was the first version I heard. (Same for Jill Tracy's "Extraordinary": I much prefer the jazzier voice-and-piano arrangement on Quintessentially Unreal to the slower, orchestrated take on Diabolical Streak.) On the other hand, I think the studio recordings of "Missed Me" and "Truce" are much stronger than the demos on A Is For Accident, and despite a lyrics change I love the studio version of "Coin-Operated Boy." It all depends on what changes. And sometimes it doesn't matter that much—I've decided I like a later, more stripped-down variant of Bob Dylan's "Tangled Up in Blue" (a concert performance) better than the bluesy, jangling original on Blood on the Tracks, but that doesn't mean I won't listen to them both.