I usually carry a flush-based ten in my G26, only occasionally using a 12 for anything at all, and once in a while, I’ll use a 17 for the spare, but usually a 15. Been doing that for about 2 years now, and the G26 is my most carried gun for that time.
I just got a 19x about a month ago, and I’ve been experimenting with carrying it this week. Been using two 17 round magazines with it, and not using the +2 19 rounders.
The 19x is my first Glock larger than the 26.