I don't want to "dis" M&PUSER or any of the other contributors, but my experience with the RCBS power trimmer was very unsatisfactory. I ended up with trimmed case lengths varying .005 to .015 and sometimes a little more (always long). This was due to a tension inconsistency in the paddle and rim thickness variation. I got rid of mine and replaced it with the L. E. Wilson Trimmer. You can find these at many reloading supply firms. I got mine from Sinclair International before they were bought out by Brownell's. I have the Micrometer length adjustment and the stand. A friend of mine has several that he sets to a length and loc-ites permanently. He has one each at 1.500", 2.000" and 2.250". (BR, 308, 30-06/300Mag). I found that the case are within .001 of each other and with extra care can be within .0005. The Wilson trimmer uses case holders based on the body of the case family. So 308, 7-08, 260, 358 and 243 (and some wildcats) all use the same holder. When I decided I liked this system I bought 12 case holders, for all the families that reload, because the price will only go up.
Another good trimmer is the Forester. I have both the regular and the "Classic", this is for large Black Powder and African cases. There are attachments for neck turning, neck reaming, and hollow pointing loaded rounds (1/16 or 1/8 inch hollows) to a depth of your choosing. (I turned the necks on 200 cases for 22BR with a cordless drill on this system. Several accomplished shooters have said that it was the best neck turning they ever saw.) There are only a few (4 or 5) collets to hold the cases. plus a pilot for each bullet diameter. All the brands use different pilots!
The speed at which you get the cases done isn't that important unless you are doing more than a couple hundred at a setting. For that Forester makes a base for a drill press that is pretty fast.
HOWEVER, much of this is a mute point. I started loading in the late 70's with equipment and books from the late 60's. Back then case length was usually listed in 1/100ths inch. For hunting and plinking ammo that is still good enough.
