Does anyone have any experience with Germanwings and TUI fly? Good? Bad? I know they're low cost airlines, and thus evil by default, but how horrible are they? Moderately so, or do they take pride in their villiany? Just thought I'd ask considering how badly people react to the suggestion of using a Berlin airport.

No personal experience of using Germanwings, but I've heard they're pretty good. As for the TUIfly flights, they're just reselling the Germanwings ones.
Cheers,
Southie