Few things:
The less money you put down, the higher the interest rate that you can expect. 20% down is the standard these days so it's going to be tough to find a lender willing to accept anything less. On top of a higher interest rate, you can also expect to pay for Private Mortgage Insurance which may be another $100 to $200 or so. So 4.25% doesn't sound too bad. Consider yourself lucky that it's not 8%.
Getting your credit pulled shouldn't ding your credit score too much. Basically, you need to be above 720 for top tier credit. If your credit score came out below that then it's going to be tough going to find a bank willing to work with you on low money down. If you got pulled from 728 to 718, that's one thing. But if you went from 680 to 660, the problem isn't so much a little ding to your credit score as it is the fact that your credit score isn't what most lenders want to see.
Finally, echoing what Joel said, unless you're an owner-occupant, forget about borrowing from a traditional lender with less than 20%. You may find it to be more like 25% down.
The 5% down party crashed back in 2008. It's over. Nowadays banks want their full 20% down. FHA will do 3% down for owner-occupants but you've got to have a pretty sterling credit and income record. I recently received a 3% FHA loan but man, they put me through the ringer. They wanted documentation for every last thing - including invoices and sources of funds for every $1000 deposit over the prior three months. (Given that virtually all of my deposits are for in excess of that, we had to do a lot of digging.)