Having worked at Microsoft should get you an interview just about anywhere. And anyone who considers it a negative is, frankly, an idiot.
* I've interviewed 3 different people from MSFT that were experts in eg a tiny area of DCOM; as startup needs generalists;
* a 30 person company is nothing like a 30K or 60K or whatever they're up to these days and it seems that people comfortable in one are often not comfortable in the other.
If someone's worked for Microsoft, it means he's probably smart and probably has experience working with other smart people to release real software. That's exactly the kind of person I'd want to work with.
The first two should never get through a resume filter, and the last seems something to be caught in an interview. Are you saying you wouldn't hire someone from Google because that company is too big?