I have run both the SX and DD3515.I had the SX on a bp1200.1 and later on an RE35.1, great sub but I like the 35E's better.
I ran my 2 3515's on 2 IA20.1's strapped at 1.4ohm for 6months w/ no problems at all. They can take the power just fine, unless you are an idiot and can't tell what clipping sounds like.