It hasn't for me and I use both often. But I don't test every possible os+browser+version combination. I add width to the style tag only if I have a style tag already.
[edit: yes that's my entire reset, but I don't make wildly complicated layouts]
Yup + I've always imagined style tags require more parsing therefore are less efficient. In retrospect this is probably untrue, but still the code is shorter so I figure why not. :)