I'm trying to get some information, currently my company has an informix DB setup, but we are looking to completely change the DB for a major project.

I've used MS Sql Server quite abit more than informix and wondered what pros/cons sticking with Informix might have.

The majority of our business is windows, Domain, Email, and the majority of our staff are not familiar with Unix/Informix either.

From a technical, performance and security view, what benefits would MS Sql Server have over the informix/unix platform?