I'm using Cytadren in my current cycle and did in the previous one.
Cytadren is hormones inhibitor( cortisol, androgens, progesteron, etc) and very effective aromatise inhibitor.
250mg a day is approximately as effective as aromatise inhibitor as 3/4 mg of Arimidex. Half life is 6 hours,so tabs have to be split in 4, take 2 quaters upon awaikening, one more 6 hours later and another one 6 hours later.
In doses not higher then 250mg a day it very effectively inhibit aromatisation but very slightly dismolase, wich is responsable for cortisol production. So, stick to 250mg a day, since low levels of cortisol are not desireable, dispite comon belief.
If you do more then 250mg a day for longer then 3 weeks the feedback mechanism will kick in and your body will start overproducing cortisol, dispite presence of Cytadren, and that's very bad, that's when you will get sore joints and other sides.
It's better to taper slowly Cytadren down, toward the end of the cycle, to avoid cortisol rebound effect and you will have to completely stop it 72 hours before starting Clomid, that's how long it takes for the body to restart producing hormones, androgens included.
I used 1g of Test and 50mg of dbol with 250mg a day of Cytadren in last cycle and got very little water retention.
Using now 1200mg of Test and 60mg of dbol with 500mg of Cytadren for 3 weeks, 375mg for next 3 weeks, and 250mg for the rest of the cycle. So far, so good!
Don't use it post cycle, no need for it.
If you have a choice, use Arimidex, the only reason I use Cytadren, because it's cheap and easily available for me, I get it from pharmacy.