I've used version 3 of Fontagent Pro for a long time and found it beat the pants off of every competitor out there. Recently I upgraded to version 4 and found it buggy to the point where I was drawing comparisons to Suitcase X1. It would randomly auto-activate fonts that had nothing at all to do with what I was working on, slow my system to a crawl in Illustrator, occasionally tell me that a font I had been working with had suddenly gone corrupt (that is, until I restarted the computer, at which point everything was suddenly hunky-dory again) and generally eat up hours of my time as I watched spinning beach balls every time I worked with certain font families that I *knew* were good. I sent a report to Insider Software but have heard nothing back, so I've gone back to version 3.32, the last good, stable version. I'll still recommend this software, just not this version.