Don't forget that Estrogen is just as important as testosterone, not for muscular gains but overall health. Obviously overly high levels have derogatory side effects but so do sub-normal levels on libido, brain function, heart protection and bone strength. Suppressing estrogen for a couple months may be satisfactory but for a whole year would be a bad idea IMO. The same ideology goes with the imbeciles that think suppressing cortisol is a great idea, sure you may be slightly more anti-catabolic for awhile but you will have to cope with a sever loss in energy, hair loss, vomiting and eventual lesions of pituitary stalk.
The best way to make gains is too put your body as close to homeostasis as you can, with the exeption of using super-physiological steroid doses for short amounts of time, if thats the method you've have chosen. You would make more gains by having your average estrodiol levels throught a cycle (and off-cycle in this case) than having that same amount halved.
This is a repost I made from the same topic posted earlier today. By supplementing a anti-estrogen all year IMO you may keep some estrogenic fat / and h20 retention off, but when you finally drop the anti-e the baseline level of estrogen related fat will inevitably return - and you will have a small amount of potential gains never acheived due to hormonal inhibition.