Alot will depend on how much you plan to shoot that new 45. If you are going to confine your shooting to several hundred rounds a year, it will not be worth your time or money to set up for pistol reloading. If you plan to shoot several hundred rounds or more a month, you might want to consider reloading.
you can buy a box of 1000 cast lead bullets for a little more then a box or two of factory ammo. A 0ne pound can of powder will reload about 700-1000 rounds. As you can see, reloading will save you alot of money.
I prefer a progessive type reloading press for pistol ammo due to the high volume of rounds to be reloaded. I use a Dillion 550 press, and after getting it set up, it will load ammo that is very reliable and accurate. In fact I used this setup to load match ammo for competive shooting matches.
As for the warranty disclaimer, most gun manufactors will not cover for reloaded ammo. It is easy to load a double charge of pistol powder due to the small amount needed in a 45 case. The use of a progressive press will help to prevent a double charge if used with common sense. I have loaded approx. 40,000 rounds of 45 ammo without any double charges or other problems.
RLH is correct that it does take a little more care to get your press set up right in order to load very consistant-accurate ammo for a semi-auto to prevent feeding jams.
RELH