It's a hard one to know which way to jump. We went digital from in-house Jan '04. Got PREPS on recommendation of vendors who helped us install and get running with our 2nd hand equipment. I've got used to PREPS and it's a powerful program, but a bit "old fashioned" in the interface and sorta clunky, unless you've got some significant hours up on it. The latest upgrade has some improvements, I'll admit.
We got Dynastrip recently, cos we had to with our new RIP/workflow, (kinda bundled, really). Although the person(s) who designed the interface needs a whack over the back of the head with a length of 4x2" redgum, am getting used to it, and once you do, it works, too.
Downloaded the trial version of ImpoStrip, and to be honest, if it wasn't for the safety factor/support relating to our new RIP, I reckon it's got the best interface. Really, isn't that what it's all about? The guts of imposition is the relation between PostScript code, and/or PDF objects and how they're arranged on the co-ordinate geometry board. Sure there's other stuff you can do, like anamorphic distortion for web etc. but most of us are arranging, saddle-stitch mags, flyers, bus cards,whatever...ease of interface is what gets you through the day, IMHO
All I'm saying is, if you have the time/luxury, test 'em all. Your decision will at least be a bit informed.
Good luck
