im currently in week 7 of a test only cycle @ 750mgs week and am taking arimi at 0.5mg eod.
I got my mid cycle test results back the other day and my estrogen levels were about 250 (give or take 20) not sure what scale you blokes use in the US but in Australia that puts me at the high end of normal.
I feel that you should use (off season) just barely enough anti-estro to do the job. Its a fine line. I do .25mg EOD. To wipe out estro totally hampers gains for sure.