What Pleno1 said 1,000 times.
I kept trying to MT and it got me some nice bonuses but playing 24 tables is tough work... It tires you out, and not a lot sinks in because as soon as you act on one tables there is at least 3 tables that also demand your attention so you just act and move on. So you are never really improving your game because you are not adapting to players the way that you should, even at the micro's.
If 4 tables is slow try switching to 8 or 9 (depending on screen setup). And if you are playing FR try switching to SH, there is a lot more going on to focus on to stop you from becoming bored like you can on FR tables.
For now if I was you I'd look at the micro's like the foundations to your perfect mansion, do you want it done quickly with no attention to detail, or do you want a good solid base that can weather any storm on which to build your investment in the future?
Anyway, best of luck whatever you decide.