When I was looking for a smaller 45 carry I didn't go for the 30 at all, and while I was dead set against polymer to start out with, shooting the m&P45c was the end of the search. Didn't care for the Glock feel at all.
So, maybe a couple of years later, I just simply wanted a 10mm gun. Period. No magic analysis, it seemed like a no brainer, and the 29 seemed like the choice. Everyone seemed to be thrilled with them, and while I had serious concerns about the size and the fact it was Glock, I just bought one--online, no touchy-feely, no rental, no even seeing or handling the gun.
Wow. My answer is real simple now. G29. I've handloaded about 10,000 rounds now, and have shot maybe 3,000 through the G29.
So, it's hard to convey just how much of a 45 guy I was until I started loading and shooting 10. It's actually quite unlikely I'll do much with 45 or 40SW for a long time to come--the cartridge is just
that nice to load and shoot.
As for personal defense, the 10 is one that is surrounded by a magic ether of horsecrap 2 metres thick--sort of like the internet lore of '40 SW snappy recoil' and other stuff that folks experience or simply relay because they've heard it so much. The 10 is even worse in terms of what appears to be just complete bunkum that folks either make up or repeat. The facts are these: it can be loaded up or down and still be 10mm and still be effective. WHen ammo is available, 10mm is available. 10mm is not available in as many exotic (absurd) self defense boutique loads as other calibers. So, if you buy ammo in 20 round boxes at $2 a round, you won't have as many choices.
In the G29 you have what I now believe is a total package of perfection. The gun isn't even as butt ugly as most glocks, IMO...but butt ugly is easily overcome by shootability and performance.
Buy it and get this over with.
But seriously, I think you'd be happy with either one and if you
don't handload and have no plans to, you will indeed find 45ACP ammo everywhere and in a huge variety. If you handload or intend to, 10mm brass isn't something you're going to find laying around at the range--I buy all my brass at Starline, and that does make shooting 10 a bit more expensive (my brass recovery even at the indoor range is only about 80%).