yea i am curious too, i have run both on cycles, i ran the sust longer 12 weeks opposed to 10 with test e gains were close enough so no diff. there, i never get ance from test (knocking on wood) so no diff there, what i did notice, was with sust seemed to me like more controlled steady gains. also i was holding a lot more water with test e. i know its personal preference, just wondering why you dont care for sust. just for the record, those were the only 2 cycles i have ever done, so im just rating them against eachother