I once thought like you're thinking right now. Here is the answer that I have found via my experience. The
safest bet long-term would be to just get into one of the better regionals ASAP because
seniority, seniority, seniority.
Despite the wonderful tales of exceptional career luck you will hear in these forums, AMFers that go directly to the majors are such a minority that planning on being one of them would be dangerous gamble of your time. If you do go to AMF, you will probably get to listen to Andrew Lotter (or whoever the director of flight ops is now) tell you how
any regional will hire you after you've flown for Ameriflight. And this brings me to a very important fact:
Most AMFers these days end up going to a regional anyway. I know an AMF chief pilot with well over 1000TPIC still waiting for the majors to call him back.
So, if you're playing the numbers for long term success, just go to a [good] regional right now and skip AMF. That is, unless you wish to tour the crappiest layovers in America as part of some cultural experience.