Timo Boll T5000 with Long Pimples

I am using a T5000 (off+) attacking blade with Tenergy 64 on my red side. I have a modified Seemiller grip, so I play the one side (Red) both forehand and backhand. On my black side, I have been playing with YASAKA Power Anti (mainly for serve return), but want to go to long pips. I have purchased both Tibhar Grass D’Tec OX and .5mm sponge to test. My questions are: 1. Which one of these two versions do you think will be better for an aggressive backspin serve return, and 2. Which one of these two versions (OX & .5mm) do you think in general is better for service returns. I know that this is not a great blade for long pips, but I am an all out attacker. I twiddle and will only use the long pips to return some serves and the occasional block, but not for chopping. I play close to the table, and am a very flat hitter. Thanks for any help.