I agree that your ARC experience depends on the region. I'm in southern Oregon and we used to use ARC in Portland, three hours north. If I called for PRBCs at 6 AM, they wouldn't arrive until 5 PM, because they would have missed the Greyhound bus. ARL was not available overnight. And they were more expensive.
We went with a community blood center affiliated with a larger group, Bloodworks NW, which is in Seattle. We're an hour from our blood center and when we send up a reference specimen, it is flown up to Seattle from Eugene and sometimes I have preliminary results the next day because they work 24/7 for no extra charge.
Plus we are supplied a historical database on units, which has been a godsend.
To me, the difference is the customer service level the community blood bank is willing to give us. And they are cheaper!