I am personally of very high opinion of Convecta Chess tactics cds and I can attest those should not be confused with some poorly assembled “freebies” on the Internet. I personally train my tactics alertness with CT Art 3.0 and it is great!
Those cds been developed based on books of Sergei Ivashenko (the core of tactics training for so-called Soviet chess school) and problems are of high quality, most important is each level is logically follows from the previous one. A friend of mine, who is a couch in NJ tells me that “his kids” accelerate very quickly after they master book Chess School 1a - which is essentially Chess Tactics for Beginners.
To Kevin:
I suggest that if you decide to give Convecta a chance, start with Chess Tactics for Beginners. While you are certainly not a beginner, you will find material in level 3 and up (there are five levels) interesting and solutions not necessarily obvious. I (2100 + USCF) actually started scratching my head (on handful of the problems obviously) on level 2.
Once you aced Chess Tactics for Beginners, you can move to Chess Tactics for Intermediate Players and here it really gets challenging, but Beginners course would be a good foundation.
~MK.