I swap between both of my R1's regularly. One is a 2001, the other a 2012. The TC is nice when I'm really getting up the throttle, and for wet weather when I'm accelerating hard and I go over white lines or paint, but on the whole it's not something that I depend on. I still have my throttle hand discipline regularly practiced keeping the rear from getting too crazy on my 2001, so unless I deliberately provoke the TC on my 2012, it doesn't make that much difference to my every day rides.
I must say, it was really useful on the track. But I had it on a less obtrusive setting so I could still get the rear out. However, if I had the choice to buy a planker with it, or without... I'd choose with. It's pretty nifty if you want to get mischievous.