I have a 3/1 ARM.
My interest is only at 4.25 right now.
People say, "It depends on how long you'll live there" or "Depends on your situation", but interest is interest. Even if you had a 5.3% on a 30 year loan, you're still paying $150 more than I am a month. Personally, I'd much rather pay 4.25% than whatever the going rate is at now
Besides, with the extra $$ you save in interest, you can just dump it right back towards the principal
It's the way to go, IMO, but don't take my word for it, I'm by no means a real estate expert.
Mine caps at 6.25, I believe, if it were to ever go that high (not likely anytime soon).