I ran tren hex at 320mg/wk, and 500mg/wk test E. I did not use dostinex. I never had any problems. I am not gyno prone and generally get very little sides from gear.
Please keep in mind that everyone is differant, and you should have it on hand just in case. I also hear so many positive sexual sides from it that it might be worth it just for that reason. Hornier, better erections, and better orgasms for some bro's are enough to convince me to try it next time I run tren.
I also have to say that when running tren hex and test I was very aggressive sexually and had some of the best erections and orgasms of my life without dostinex.