I never seemed to mind trimming so much, but what I really hated was the chamfering. Then I tried a Lyman chamfer and deburring tool in my Lyman power trimmer and it worked sooooo good. Just chuck them up and slide them forward and they are done.
I use the Lee trimmer. I chuck the lockstud in my battery drill. Put the case in the lockstud and touch it with the trimmer, about 2 seconds and it's done. Two quick trigger pulls and it's chamfered inside and out. It took me 4 to 5 hours from start to finish, sizing, trimming and all.