Did you have any specific symptoms or problems that you attributed to smoking that you feel haven't gotten better?
I didn't have too many 'noticable' problems with smoking. I didn't have a smokers cough. I wasn't wheezing or having trouble breathing. I exercised a lot and didn't really think that the smokes slowed me down that I could notice.
ETA: I forgot to mention that when I was smoking, I would feel some deep chest pains, usually lying in bed at night. Those would always scare me, but I can't pinpoint exactly when they went away. I think it took a while.
It may be that you have some improvements that aren't so obvious. Your CO2 levels have probably decreased. Since I work out with a heart rate monitor I know that my resting heart rate has decreased, but this is not something I'd know if I didn't have a record of it before hand. If you had blood work done before you switched, you might find that some of the numbers have improved. Your blood pressure might be better. If I look at pictures of myself now compared to a year ago, my skin looks noticeably better. It's pinker instead of kind of grey, and I look, um... younger or fresher I guess I'd say.
Anyway, maybe you will notice more dramatic changes as you give it more time. If not, at least you know you smell better!