I've done both.
I ran Sust at 750 per week and Dbol at 40 mg a day.
I ran Sust at 750 per week and Tren at 100mg ed.
I gained more weight on the Sust/Dbol cycle, but it didn't look as good (water weight) as the cosmetic changes I made to my body on Sust/Tren. Also, I got more strength off the Sust/Tren.
My two cents, and from personal experience.... a test/tren combo is the best stack out there. It basically took my 210 pds and by the end of the cycle made it look like it was 240...when in reality it was 219 at the end. All of my friends and gym buddies were under the impression I had put on a ton of weight. But, if you can put on 10 pounds of no-bullshit rock hard muscle, it is equivalent to a metamorphis. And oh by the way, test/tren also gave me the best strength gains I have ever had...better then Anadrol and Dbol.