Fella's;
I've been using and reloading for the .40 since the middle 90's. No problems with reload rounds whatsoever, and thousands of them. It does do something the other's can't, it puts superior capacity on a 9mm frame with the terminal energy levels of the .45. It didn't get to be as popular as it is by being a bad round.
However, the O.P. has the self-defense aspect covered with his current 9mm. Unless there's a desire to shoot a competition that demands the 1911 frame and the ability to make major, it'd seem to me that a revolver larger than the .22 might have a place in his safe.
Start with the idea of a .357 magnum, which can handle heavier bullets than the 9mm, and doesn't spit brass all over the place. There are thousands of used .357's on the market at just about any given time, perfectly good guns at better-than-new prices. Easy to reload for and as versatile as you can get. Or, move up to the 44 magnum. It has much higher energy levels than anything, including the .45ACP, that's been mentioned. However, it also brings increased recoil with those energy levels. It also can be easily handloaded, and is also a very versatile round. Or, go into the territory of the boomer. Hand cannons aren't for everybody, but it you want one, go for it. Again, lots of low-use guns on the market from guys who thought they wanted one, and then about two boxes of ammo later, decided they didn't. Best to go to a range, or tap a friend who has one, and try before you buy.
900F