I did this in reverse on June 18, leaving MDT about 6:40 PM, seated towards the rear.

The a/c was full, but it departed on time and arrived in ATL a few minutes early.

The FA made one pass with drinks/snacks, but then came through a few more times passing out water.

If you can get an aisle seat and don't expect too much in the way of service, the trip is totally bearable.

There is gate checking for carry-ons at both ends.