My highest and lowest sessions were in the 5 figure range (cash game player, not tournament), so I was never up in the really nosebleed stakes, but I was high enough up that a lot of the nosebleed players would play in my games. Some of them have an impressive ability to play their A-game even when switching between games an order of magnitude in stakes apart. Some of them, uh, don't. People you've seen on TV are overwhelmingly more likely to be in the second category and were generally welcome in my games, at least for monetary reasons. (There was an old screenshot of Phil Hellmuth sitting at a full 9- or 10-handed 300/600 limit hold'em table online. He's out of chips and every other player is sitting out, waiting for him to reload. I have a pretty similar live story about him.)