I bought a Framemeister years ago when I added an NESRGB board to my NES. RGB made it look like a whole new console. I then bought all the cables for the rest of my systems. Modded my SNES Jr. (only the old SNES outputs RGB without a mod), and was living the life. Then, early last year, I was able to pick up a 20" PVM free from work (looks just like yours). It was in MN, so I packed the living hell out of it and shipped it to myself back in NJ. It's so much more enjoyable to play on there than on the Plasma with my Framemeister. Now, the Framemeister just sits there. It's a sad story for the little guy.
Then, a month or so ago, I picked up a 14" PVM for free (well it was broken). Fixed it up and we used it at the tourney.
Worked at a museum in Phili last week, they has 2 PVMs and a BVM laying around. I'm not sure if I can take them though. These things went for big money back in the day. Now people just rip you off on eBay selling these. I think PVMs were $2-5k new (depending on size), BVMs (Broadcast Video Monitor) were in the 10k range.
The reason they are so much better than a traditional CRT, is the line count and the quality of the tube. A line count on a reg. CRT maybe below 300 lines. On a PVM they are 600-800 lines (depending on the model). And the tubes are made to last a long time.
Even playing on a $20 CRT, composite video looks much better than on an LCD.