I have discovered that at microstakes ($10 or $20 NL)I do well multitabling, usually 4 tables. I am doing my best to stick to the 5% of bankroll for buy in rule. Although I am making a profit, sooner or later when my bankroll allows, I will be moving up stakes. At the mo, I play these games like an ultratight robot, I have no reads, no notes or info about any of the players at any of my tables. My question is, at what stakes do you have to mix your game up and maybe stick to one table to give you the chance to make notes on players etc. I get the feeling that maybe this style of abc poker would not work if i got up to say $200 NL

I think it does'nt work at $50NL up, depends on sites. I have seen quite some call bluff and raising with 67s LP at those tables.

Multitabling is a skill that gets easier with practice. It might help to play your regular robot game at three of your tables and allot as much of your extra attention as possible to one of them. Eventually you'll feel less rushed and you can get some reads on your opponents. I used to feel overwhelmed playing 4 tables of .50/1 LHE on Paradise (the slowest site I've ever seen) but now I can handle 8 25NL tables pretty well.

As for stakes, I can't really answer that as I never played above 50NL, but I 4-tabled that for a very good BB/100 on FTP.

If you're not using Poker Tracker with a HUD, I'd highly suggest you get both. They won't take the place of actual reads, but it's a lot better than nothing.