Yeah, I've used deca in four of my cycles (including the one I am currently running). No doubt that deca is one of my favorites. Nice quality gains, it has helped heal injuries in my elbow, knee and ankle. Get strong off of it. Only have to shoot it once a week. Relatively pain-free shots (even with high-concentration gear).
I will say that I'm at the point where I don't like running deca throughout the entire cycle -- I believe (as some others do) that it has adverse psychosomatic effects when coming off (depression); plus it does shut down the HPTA fairly hard and is long-lasting. For these reasons, I will run it the first five weeks (with test), then cut out the deca and increase the test dosage for the final four weeks. This way, the deca will be out of the system by week 8 or 9 (yet the test will still be there to keep gains going and the spirits high) and I can start my post-cycle therapy 2 weeks after my last shot of enanthate.
If I were you, I wouldn't go over 400 mg for first time with deca. 600 mg seems to be the upper limit when talking risk/benefit ratio. I wouldn't go there until you're really sure your body likes deca -- it takes a long time to get out of the system. I still shoot it at 400 mg with great results.