My style rule: If you have to maintain the someone elses code style, your sanity level will approach the sanity level of the original developer.

I've worked on a large code base with many developers in the past. In general it is a good idea to keep the existing author's style especially if they are still maintaining the code, and it doesn't drive you crazy. I don't look at it as losing myself, but rather being able to adapt.

That said, I feel your pain. My sanity took a hit a while back when I had to maintain a fair amount of code that someone reformatted to their "taste" since they didn't want to maintain the original style. This taste included making lines go past 100-columns by using crazy indentation rules and lots of levels of indentation, introducing non-English comments and variable names to code written entirely in English, and using huge variable names (>60 characters long in some cases). This made it impossible to even diff the code against previous releases and determine what changes were actually made, even with a version control system. My choice was to keep with their "style", reformat the huge amount of code again, or find other work. The other work is working out just fine...