Chess Tactics Trainer Question

I hope an Expert can answer this. 

I understand the TT mentality of pattern recognition and the timer to learn to move quickly.  I have been dedicating an hour a day, at least, to TT.  I used to be at 50% success rate and about 1300.  I advanced to about 1500, with the same 50% success rate, moving quickly, and now recognizing more patterns. 

The problems that are above 1500 do not seem to always fit into one of the tactics motifs.

There is something else:

This tactic shows a quick mate.  Yet, in replaying the position, I would not move where I was quickly mated...

so I tested it against the computer, at 1200 and 2000.  In both responses, the computer does not play the position that the TT played, avoiding quick mate. 

http://www.chess.com/tactics/?id=300497

Is it best to continue to play the tactical motif tactics (other websites) until all or most are recognized so that "1500" shows up with 75% or above success?

Or, do I just continue on this particular TT seeing that the more advanced tactics are sometimes positional?

I am grateful for the advice.  

I am a tournament player, I will give you my oponion.  I would continue playing this Tactic Trainer, sometimes tactics are positional.

Try to really give time to think over the problems and try to get above 90% on correct answer, do not worry about the time. Sometimes on really hard positions I take 10-20 min to think it over, but the whole game depends upon it.

If you miss the correct answer think it iver again, see against the computer what would have happened if you played that move, you have to understand why that move was incorrect, never leave there a doubt. Usually when I analyze my own games I Take 4-7 hours to analyze a game and I shred every move to pieces until I see all my thinking deficiancies.