you should try chesstempo
http://chesstempo.com/chess-tactics.html
Usually I do the 3 TT problems after working on tactics at chesstempo. It definitely helps. I'm better at spotting tactical opportunities OTB, and my TT rating has improved. (I know I'm seeing opportunities better OTB because I play on Monday nights at the chess club, and I've been doing better against players who usually beat me.)
yep, for a year I had Diamond membership. I like the Chess Mentor, but I didn't watch so many videos. I do like to play through annotated games of Grandmasters, such as the games of Rubinstein annotated by Kmoch, the games of the famous New York tournament (late 1920s) annotated by Alekhine, the games of the 1953 international chess tournament annotated by Bronstein, etc.
Currently, Basic members are allowed 3 TT problems per 24 hours. How about 3 TT problems per 12 hours instead?