Im finishing my second cycle, the first one I ran the test higher than deca. This time I used npp instead normal deca and test prop instead of test e, kept my deca higher the whole time and felt much better. I also made way better gains, but the best part was just feeling better, I didn't have any sexual problems on either cycle so I can't answer that for you. If your going for deca, try npp, I love it and I think most guys will agree that it's better than using a longer ester deca.