Prophet on national TV. The American Idol backing band keyboard guy has a Sequential Instrument pretty prominent in his keyboard array. Not really sure since it looked shorter to me, but I think it was a Prophet 6. Just an observation.
I notice the P6 on stage fairly regularly.. I'd say more often than any other analog that comes to mind. I think there's a number of reasons for this. Fairly compact, versatile, punchy and cuts through, very immediate to program, solidly built, etc. Some other choices like Prophet 5/10, OBX-8 might be a bit large to gig with for some.
I've thought about this from time to time, if I were gigging and could only take one of my synths which one would it be? Probably the P6.. Not because it necessarily is the best sounding keyboard I own (although its certainly a top pick), but because of the specific combination of the factors above. It's a great board for my use (studio) but it also has this "stage personality" where it sort of begs to be taken out and gigged.
It kind of makes sense, as it was well known that one of Dave's favorite pass times was to go to live music events and he enjoyed seeing his creations being played on stage. I think that fact influenced many of his designs.