Yeah, I broke both my Slog and Bristleback while transforming them for assembly into Monstructor. In the case of Slog the damage was non-essential, but with Bristleback it was part of his leg. The robot head of my Transmetal Megatron broke about 5 years ago; fortunately I was able to easily (and affordably) replace it with a Metals Megatron.

I was discussing this with kup a few days ago; one Transformer on my want list is G1 Roadblock. It's a toy I never got as a kid because the Pretender Vehicles never interested me (I got Gunrunner as a gift); they're underwhelmingly crap toys and didn't appear in G1 canon. Then Roadblock appeared in the BotCon Japan exclusive comic "Cybertron Chronicles" which has since put Roadblock on my wants list (although a low priority want). The thing is that I always want to play with any toy I get, but I know that if I get Roadblock I won't want to play with him in fear of damaging the inner robot! So I'm at odds... part of me wants the character, but another part doesn't want the toy if I can't play with it. Gah. I probably will eventually get it but it will be one of very few Transformers in my collection that I'll never play with.