3.375% which didn't seem like a huge drop, but getting out of the ARM felt worth it to me. I guess I was also hesitant because I didn't/don't know how long we will stay in the house so I wasn't sure if we would recoup closing costs. So far we are still there and I am happy we did it.
The reason why we ended up with one was because I think it was the only way we could qualify for a loan with 0% down. We were just out of medical school and wanted to buy a house, but obviously not enough money for a down payment, so we ended up an ARM.