It depends on what your needs are. The guys are right, most of them are glorified power strips. That said, I have a Furman because I like the lights and the voltage meter. But, for serious electrical issues (like gigs in Nederland), I do use the voltage regulator version (model number escapes me right now). It's an older one. Since I dropped my Lexicon LXP 1 and 5, I haven't really needed but they got squirrely in a hurry when the voltage dropped.
For my location recording, I use a double conversion sine wave UPS. It's crazy heavy and runs off the batteries full time with a brand new sine wave. If power gets funky I have 10 minutes or so to save my files and deal with the power. Luckily, I've never really had to use it since I got it. It has just enough capacity to run my computer and interfaces. For bigger shows, I have a monster double conversion Liebert, but it's too crazy heavy so it stays in the shed.