I don't really like playing more than one table. For one thing I play super-shorthanded (basically I play HU and ring tables with less than 4 people in them) so I have to pay more attention to the gameflow to adjust, and for another you're basically playing less of your A-game the more tables you're playing -- and you can't really get better because you don't have time at all to reevaluate your assumptions.
I dont multitable when I play live. I do online if there are tables available that I like the stats of . Ie. percent seeing flop/ avg pot size ect.Or noted players that are exploitable on several tables. I disagree on the latter ""you can't really get better because you don't have time at all to reevaluate your assumptions.""
This is why it is important to take good, dated notes, fully utilize your HUD while playing than playback each session you play. plenty of time to reevaluate and note what you/others are doing right. What is exploitable and what leaks you may have and plug them. IMO regarding online ring games, during the session is not the time you improve your game significantly, it is thru the evaluation of it afterwards and the notes u make that improves your game the most.
IMO if a player was to play, multi table or not, with the intent of maximizing profit. Without good notes and decent software ie HM PT, and study poker sessions. It would be comparable to a student that attended a college course and only showed up for class but did not study or take notes. Granted they may pass the class but obviously could of achieved a much better grade and general knowledge of the subject had they taken notes and studied what was presented during class.
Honestly I am not the best at doing that myself but my focus is more on live these days.
I can assure when I walk into any of the places that I frequent I can look around at the tables and any player that I have played before I will have mental notes on I may not know their "real" name but my brain knows their names , nit, fish , tag, rock, lag, gambler, crazymofo. As well as their starting hand ranges and tendencies