Another vote for FontExplorerX
I'm almost wondering if those that are praising Suitcase and knocking FontExplorerX are using the same two programs that I've used...
last summer I purchased Suitcase X1 (most recent version before Fusion). It seemed to work OK (I have about 4000 fonts - mostly PostScript/OpenType with some in TrueType/.dfont), but it took forever to load (even with just my 200 font 'standard' set) would crash all the time, would just randomly slow my computer down, annoy me with it's strange interface quirks and non-intuitive group/set management, etc. and ultimately have me upset that I spent $100 on a piece of software that just made me even more frustrated and annoyed with font issues. I was tempted to just trash it and go back to managing fonts by manually moving larger sets as appropriate in conjuction with FontBook...
until I came across FontExplorerX. Not only was it free, but it was faster than Suitcase in loading, seemed much more stable, fast, intelligent, complete (even as an alpha), better designed, more intuitive, and generally without any major problems. Yeah, it wasn't quite as fast as I had hoped, and it at times has a hiccup, but it's light-years ahead of Suitcase (or maybe it's just a testament to how AWFUL of a program Suitcase is). The activation dialog can get a little annoying, but I find that it tends to actually work in practice better than Suitcase did - and I tend to just group my fonts into sets and will activate them in the program depending on what I'm working on/doing. I can even activate a group/set in FontExplorerX after I've opened a document and realized that one of the fonts wasn't active - and most of the time that's sufficient and the correct fonts will display - though occasionally I have had to open the document a second time or maybe once or twice reopen the application (both times I had A TON of my fonts activated as I was messing around with some design ideas and got carried away).
Obviously, choosing a Font manager is a highly personal thing and depends a great deal upon your workflow, font usage and the phase of the moon in relation to the reasoning behind U.S. Foreign Policy (which means it's all a bunch of voodoo that defies any sort of rational understanding or relation to intelligent thought). Maybe Extensis has greatly improved Suitcase in Fusion - just about anything would be better than the awful X1... unfortunately, my experience with that program soured me on Extensis, and I'm not willing to throw out another $50 or whatever they're charging for the upgrade just to be disappointed again. I'll take a generally well-built, intelligent and amazingly free font manager like FontExplorerX any day.
P.S. Anyone know if Extensis allows the transferrence of a license for their software to someone else? Anyone want to buy my copy of Extensis Portfolio 7 and Suitcase X1?