I have completed the level 40s, and scored about 64%. Not too bad. I'm now repeating the ones I didn't get 100% right, iterating through them until I do. I did this with the previous levels and found it a good way to improve.
Also, my 5 0 blitz rating on ICC has improved - my peak rating is now 1421. My goal is to try and reach 1500 which now seems in sight rather than a distant dream. I am certainly improving. Mostly this is as a direct result of the tactical training. After one year of tactical training this peak has risen by just over 100 points. Not the 400 points in 400 days though! But then I do have a job.