As a person who flies on the M88s and D95s quite frequently, I have experienced many different scenarios with bags. I have yet to fly on a M8K but, I would assume that it would be more like the D95s (because of the D95s modern interior).

I have only *ONCE* been required to gate-check a bag on a D9X (they had the same bins) and that was only because it was 100% full and a family in F decided to put every bag they were taking on their trip in the overhead bin--which extended into Y. Otherwise, there would of been room.

However, on the M88s the bins are much smaller and don't fit as many bags. I flew on a 85% full flight from LIT to ATL and we had to gate check our bags (boarding in zone 3!). And then, on a flight that was 100% full from IAH to ATL EVERYONE (zone 3 and 4) had to gate check their bag.

A lot of times (as a NRSA) we are boarded in Zone 2, but I have seen many people board me in Zone 2.