I use a 34sx955 in my bedroom, which is the exact same tube as the xbr910 (and I believe the xbr960 as well). Still love love LOVE it. Bought it in November 2004 - must have at least a few thousand hours on it by now, and the picture quality is basically as good as the day it was purchased. Never had any major issues. There is a baseball-sized minor anomaly/blob on the left side of the picture that shows up only in the blue channel, but it's hardly noticeable during normal viewing and I can't even recall when that happened or if it just came from the factory like that. Big honkin' tubes like this are never going to be perfect, but I still think they're the best quality video displays - then again I like tubes & vinyl for audio so that should clue you in a bit on my preferences.
I recently upgraded from a Denon 3910 dvd player to the cheapest Panasonic blu-ray player, and the difference is not lost on these Sony CRT tubes. The super-fine pitch tubes (xs955, xbr910, 960) supposedly can resolve up to 1440x1080, and it shows. The other tubes of this era (Sony hs410, hs420, xbr970, etc & most non-sony brands) resolve something like only 800x1080, and the difference is VERY apparent (they show visible black gaps between scan lines). I would not recommend going that route.
If the tube is in good condition I believe you'll find the color quality, resolution during high motion, and dynamic range are unsurpassed by anything on the current market. I keep getting *almost* seduced by the nice 1080p Panasonic plasmas (and their dropping prices), for the sheer sexiness of the screen size & slimness, but for a bedroom the extra screen size is not needed and I remind myself that the tube image quality is STILL unsurpassed by even these very nice plasmas (with the exception of a full 1080p resolution). So when the tube dies - THEN I'll get a 42" 1080p plasma. LCD sets are out of the question for me, and out of this league of picture quality for viewing movies in low ambient lighting.
I say go for it, if you have a way to verify the condition of the set (though at $200 you're not risking much). Just one more thing - you do know these things weigh 200 pounds, and are unwieldy as hell, right?
Edit:
The best video quality with these sets will be achieved over an HDMI connection. You mention use as a computer monitor - these are NOT the right sets for that. Get the CRT tube for video and a cheap LCD for computer work. The problem is that the highest progressive resolution on these tubes is only 540p - not enough for computer work. You can feed it 1080i, but you'll quickly find out how ANNOYING it is to have lots of sharply defined horizontal lines (which you'll get tons of with any modern computer user-interface) displayed in an INTERLACED fashion by a CRT gun. All those lines will flicker like crazy and drive you nuts! Interlaced works just fine for video (in fact this set looks its best when fed 1080i from a blu-ray player), but the phosphor persistence doesn't quite cut it with all the clean lines in a computer GUI.
