It is quite true what SystemsTrader stated. Skilled counters will look for the tables with the best advantage to sit at, or at least they should. Although its a plus to have less players at the table, its not what makes the decision to sit there or not. And sitting at a less crowded table is beneficial due to being able to play more hands and being more in control of the cards during the positive situations, not at all due the more quiet environment. Hey you could have 2 of the most loud obnoxious drunks sitting at the table with you, or 5 very quiet polite players. It makes no difference how many sit at the table as far as distractions go, if you can't count because of a loud environment, you need to practice more, because I've never been in a casino that has librarian type pit bosses shshing people to be quiet.
And as far as people being better players at higher limit tables, thats absolutely false. Those people playing higher limits only do so because they have more money from what they do outside the casino not in it. They all still make the same type of mistakes, actually sometimes worse. A lot of so called high rollers are under the impression that since they have a big bet up that entitles them to play different than what basic strategy suggests, and the bigger money will fix it all in the end. Last month I played in the same pit as Charles Barkely and watched him drop $600,000. His average bet was $35,000 and he was probably one of the biggest butchers of basic strategy I've ever seen. I believe he was lucky to only lose what he did. But the point is, all that money didn't make him a better player, just a bigger loser. Its just a shame a bankroll that big gets wasted on those who don't know how to use it.