With Delta, I actually love boarding a "full flight" where they start calling for gate-checked baggage. I will often ask the desk agent if I can gate check even if they aren't calling for it yet, sometimes they'll do it.

Once you hit Delta status tiers you end up with enough free bags that you can skip asking there and just set it up before you go.

If you don’t have status, your strategy is a great one. Delta is pretty good at not trying to charge you in that circumstance. It also helps the flyer’s case that their A321 mainstay was configured with a cabin that provides insufficient overhead bins.

Funny. I know my suitcase will always fit the right way in a 737 bin (front upwards, top handle facing the aisle) ... but on an A321 I almost always have to lay the handle to the right, wheels left, taking up unnecessary horizontal space, because the upper part of the bin isn't deep enough to close given top thickness of the suitcase - even though it looks like it fits in the lower lip before you try to close it. So these days if I see I'm getting on an Airbus, I have to try to get in early and grab the extra bin space. Whereas if it's a Boeing I'll usually be at the bar until 2 minutes before they close the gate..

I definitely do this if I have a layover with a long wait or have checked luggage anyways. Why would you add 10-20 min extra wait after landing to not pull a stroller for a few Min?