I am using sustanon 300 at 600mg a week for 14 weeks kickstarted with 40mg of Tbol for 4 weeks. Week 3 is about over and so far sh*t is unreal. A lot of guys knock on sustanon, but from what I can tell it's been working like a mofo for me already. I think everyone has their preferences, and some things work better in some peoples bodies than others. This appears to be working like magic for me. This board seems to like either Test-E or Prop. Other boards really like sustanon. I'll be better able to answer this question in another year as my cutting cycle this summer will be with test prop, and next bulk (winter) I'll probably run a single long ester test... but until you try it for yourself it is really just speculation. Human biochemistry is a science, but I'll tell you this, we ALL react differently to different things. What works for me may not work for you as well, and vice versa. There are general guidelines that we all follow, but to claim something as FACT is kind of foolish.
I say go for it. You may want a kickstart, you may not. No need to stack another injectable though. Hope that helps.