I'm sure that no school is going to tell you not to send a letter from a resident. After all, it meets the requirement that many have for a DO letter. But it may not be in your best interests.
Strong, positive letters aren't just about someone saying "Hey, this kid is awesome!" They have to say it the right way. There are clues in letters of this type, specific word choices that convey subtext, for instance. If he says that he thinks you are a "solid" choice... that can sound good, but mean something unflattering to the savvy letter reader. Rocks are solid, after all, and this can be a soft way for a letter writer to advise the schools that they think that you are as dense as a fieldstone.
The more experienced the letter writer, the better chance that they won't accidentally damn you with faint praise.