I've been a big fan of the .45 since I started shooting 15 or 20 years ago. I started reloading for it soon after because of the cost of ammo. I've tried a lot of powders and then learned a lot when I started shooting limited USPSA with the .45. With those big heavy bullets, I tend to keep away from the slower burning powders. I think that the power pistol is better suited to high pressure calibers, like .38 super.
For .45 my absolute favorite has been Accurate No. 2. A pound goes a long way, it meters really well and isn't super dirty. I guess my liking for No. 2 runs neck and neck with Winchester 231, but 231 has been hard to get where I am, so I've been using the No. 2.
Of course, I'm talking about loading for a 1911. If I'm loading for something else that doesn't run well on the fast powders, I'll just go for No. 5, which is a bit slower, but still considered a fast powder.
Generally speaking, running a faster powder will also shoot a bit softer. Just don't go trying to load any hot rod loads with a fast powder. If you get to around the max charge and still want more, then go with a slower powder.