It's a hard position to be in.
I know i don't like the hard sell, if you push me, i loose interest, but as a salesman, you need to not be too pushy but persistant to get the deal. There is a limit of what you can do to be the "nice guy" If people like you, they will pay and be happy to deal with you again.
The next issue is, say there is an issue, just how far can you go to help the customer out? if you can show you are doing everything in your power, it goes a long way, even if you don't succeed.
Good luck though, i hope we hear about your success with your new job prospects