If you haven't tried 6 max yet, give it a shot!  That's the main reason for this post.
My new favorite game is the ‘6 max SNG’ - It's structure is much different to the ‘9 max SNG’, such as, it’s a turbo format (5 minute levels not 10); it has a shorter starting stack (1000 not 1500); is easily less than ½ the time.  There’s more action, because of its structure - I really enjoy playing the LAGgier style, that 6 max rewards.  Normally I play a safer, smallball style, that lends itself better to a slow format game.
Early last year (when I was learning NLHE), I would never have thought 6 max was a game of skill.  There isn’t enough time to work your stack; too many players playing aggressive; losing one hand, may drastically limit the way you play the rest of the tourney. You definitely don’t want to be a tight player, but at the same time you need some restraint; I like to call it ‘Controlled Aggression’.
I’ve played slightly more games of 6 max this month (January 2012); compared to my 9 max games, for the entire month of December (2011).  I won as much this month (2/3 into the month), as I did the entire month of December (in which I only played 9 max).  An added bonus… it only took ½ the time, to win the same amount!  Prior to the 9 max games, I played a lot of 27 man MTT's, which require a larger time base.  I have the time to play longer structured games, but really enjoy the pace of the 6 max game.  6 max allows me to squeeze in a game (or three) when my time is limited.
I play three tables at one time, and am getting ITM around 50% of the time.  The trade off for multi-tabling, is that you will miss out on a lot of important reads, thus lowering your ITM percentage.  On the flip side, you can play more games in the same time span, which could possibly increase your winnings per hour!  You need to find a balance at which you can max your winnings per hour, and still play a comfortable game.  Unfortunately, I can't keep up with the note taking while multi-tabling.  If you try to keep notes on PS while playing, you'll get bumped from the note section when it's your turn to play; at 6 max, that comes around fast.     I may try to jot down critical info on paper, and then add them to the HEM notes during my review (at the moment I only use PS notes).  I find the color-coding option that PS has, is very good for labeling certain types of players.  Players come in many different varieties (like Heinz ketchup), and I could really make use of a 2-color system (per player).  Maybe an outer and inner ring, or perhaps, a top half and bottom half ring, could be a workable add-on (software wise).
I recently read this on PS (pros commenting on the TCOOP format):

Thanks for taking the time to read my blog.  I hope you enjoy the 6 max structure PS has to offer, as much as I do.
May the cards be with you!