For the longest time I was quite unable to gauge my own improvement or performance. I think, in some ways, perhaps my brain just isn't wired that way. I keep thinking that I'll have no idea what, if anything, could improve - until one day something does, and I do notice it. I still feel a little disconnected from it all; sometimes I forget the bunkai, and the details of what I'm doing, but I'm not remotely the same waving-the-sword-around person I was when I started. (I honestly can't believe sometimes, that it's been a year and a half.)
My worst fault, still, is speed. I move too quickly. The jo-ha-kyu will come with practice, but the rest of it I still have to work on. I think part of my problem is simply that I hate making people wait, or I fear I am making them wait, so I rush through things so that I'm not holding everyone up.
Slower iai's more luscious; a samurai never rushes.