Re: Which is correct,please?
As a concept, I'd advise against this. It creates the idea that your product user had a low opinion of your product to start with. Simply being "better than you expected" doesn't sound very positive. "Gee, I thought it would completely suck, and it didn't. It wasn't very good, but it wasn't truly awful."
As a matter of grammar, only "More Xing than expected" works, or "More Xing than you expect."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.