The BeoVision 7 televisions are incredibly well made, with substantial, machined aluminium floor stands of a strength and quality you simply won't find anywhere else in consumer products - this is where the B&O price comes from.
The TV panels give a fantastic image - best-in-class from their time - but beware; the early models had limited or no HD capability, with only analogue or DVI inputs which make connecting any HDMI source a challenge for audio. The later Mk5 models, with 2 HDMI ports, are the ones to get, but attract a price premium.
Sound is simply unmatched from any other TV; the 7-1 or 7-2 stereo sound bars are just about perfect, but even better is the 7-4 mono speaker used in a surround setup with 2 or 4 other B&O speakers. This is where these TVs really shine - peerless audio.
In summary, they're great used bargains these days, but do your homework before buying to make sure your chosen sources will connect properly.