I'll point you he http://www.gryphon-inc.com/White_Papers.html

I've had extreme success with Powervar/ONEAC products. Like 25 years on a very critical computer system. The only failures were mechanical like fans and floppy drives. The hard drive was on 15 years before the system was upgraded. It did cost about $1K USD in the 80's for about 1000 W. Later, two other systems got the same technology.

Usually, the warranty and the sales receipt helps a lot. Less critical systems got the tripp-lite isobar which oneac doesn;t like either. I did see an ISOBAR fry and Trip-lite replaced the connected equipment.

I had an APC surge suppressor (given to me) and it's is supposed to be replaced because it causes fires. I think it's been close to 3 months now and no replacement APC. Furthermore, that APC did not protect itself. Oh maybe it did? It prevent itself from frying by blowing a thermal fuse and passing the surge to the equipment and lighting a LED.