I have a variety of PCI Macs from c. 1995-97, which (excluding my beige G3s, which are PCI too, of course) comprise a 6500, 7200, 7500, 8600/200MP, 2 x 8600/300, and a 9500. I also have a Power Computing clone somewhere or other. So I for one am a fan of these machines, mostly because back in their day, I used a Performa 600 and yearned for one of them, read magazines, drooled liberally, etc. — all to no avail. No joy at the time, I suppose, led me to collect them with some enthusiasm in later years.
One of the 8600/300s has done sterling daily service as an ASIP 6.3/MacOS9.1 server for years. Another has been my daughter's computer for some 5 years. The rest, with the exception of the MP machine, get only occasional use, as there's only so many that one can use....
The PCI Macs are really my favourites of some 50+ Macs. I think the 604e was a great processor; I am not a particular fan of the G3. A 9600 would be bliss (I have never actually seen one, never mind owned one, despite my years of looking.)
As with any old machine, of course, much depends on what software you are running on the hardware. Though any machine from the mid-90s is very low-end these days, I find that with the appropriate system and software tools, these machines are very competent performers for most of what I do. Were it not for the web and the problem of software compatibility (files sent to me in Open Office Format, for instance, or docx Word files), I can't really see what more I would need for the work side of things. I am not a gamer, so that doesn't matter to me.
I too have noticed how cheaply this range of vintage Macs can be purchased, by comparison with both the older and newer machines. Good time to buy them, I say; the low prices can't last forever. I suppose the perception to date has been that, as they date from the peak period of Apple's financial distress, they can't be any good. Truth be told, however, the problems of the mid-90s resulted from the software drift and the abortive Copland project and associated hang-ons rather than from the defects of the hardware. Had these latter been successful, the hardware they were developed for and on would undoubtedly look better in the eye of beholders.