2400 here. First trimmer I've owned, as I'm new at this. Nice sharp cutter, spinning the cartridge not the cutter makes for a nice level and square case mouth. The micrometer is handy for fast adjustments when you're *close but not quite there*. I've used it on .223 and 7mmRM. Also .204, be forewarned it takes a different cutter head for .17 and .20 calibers - a fact I discovered AFTER I did several hundred .204 cases, slowly, clogging the cutter head every 15-20 and cursing a lot. Neither does the 2400 come with a pilot for .20, I had to find that separately at a different store.
The case holding function is the bees knees, very fast to use and easy to get in a rhythm of grab a case, stick in the unit, turn, take off unit, repeat.
I have it just screwed into the frame of my bench, quickly removable to recover space but rock solid when screwed in. Also has attachments that screw into the body of the assembly for cleaning both small and large primer pockets. Not as precise maybe as a hand held tool, and a little awkward for me because of the angle I have the unit planted on the bench, so not always used.
I give it 8/10 for the overall package and 9/10 for the cutter itself. My one and only mild beef is that the cutter forces some of the shaved brass onto the pilot, and the cases can be a touch sticky coming off the pilot especially if doing a substantial trim ie .005 or more.