Honestly this tactic is sublime, simply amazing. The best I have used on FM13 by an absolute mile, a piece of genius Nezza!
I stuck this on halfway through a season in which I was struggling to score AND leaking quite a few goals, this tactic has completely turned around my season. In particular the defensive side of the tactic is quite brilliant, it's so defensively sound that the opponents rarely score. I have been using this tactic since December and I'm now on the 3rd of March and I've already kept more clean-sheets than I did for the first part of the season.
Offensively it's not amazing, you don't score loads every game, although it is possible for me to score quite a few it's a bit inconsistent but with the defense all you really need is 1 goal and you have a huge chance of a win so it's really not much of a problem for me.
If you're debating whether to use this or not do not hesitate, this is hands down the best tactic I've used, plug and play just like FM12.
Thank you Nezza for turning my season around!