Back in the time before Covid, I shot a shotgun match with a borrowed Mossberg 590 DBM. I was very pleasantly surprised!
Chap had three ten round magazines. They were a little fiddly to load, but would undoubtedly be less so after doing it a few times. The gun is quite heavy with 11 rounds, I'd say over 10 lbs and the 10 round mag was unwieldy hanging down as it does, so I would prefer five round mags, but may changes were easy and I don't recall having a feeding issue. I was very positive.
FWIW, another chap at the same match had a AR(ish) looking semi auto made by RIA and I was very impressed with that as well.