How do these 2 balls compare?

Thanks!

they roll very similar imo, since they are both in the masterline and are reactive solids

I don't have exactly the same drill on my Special Agent as on my Dimension, but they are pretty similar.  Look here:
Dimension
Special Agent
Comparing both at 2000 abralon, the Dimension picks up strong in the midlane and starts to corner, then continues to make a dramatic move on the backend.  My Special Agent doesn't pick up quite as soon and makes more of its move on the back part of the lane.  Only a few boards difference in total motion probably.  The Dimension's hook motion is a little more continuous while the Special Agent straightens out just a pinch more.  I actually left more 9 pins with the Special Agent though since I had to get it into the friction a little earlier and harder, so it would come back too hard sometimes.  I feel like the Dimension is a much more forgiving ball.  It's basically just a newer, better version of the Special Agent.  It's everything I loved about my Special Agent, just improved and tweaked.

I actually don't have an x-hole on that Special Agent by some miracle.  The first one I had with that layout required one (that ball bit the dust and cracked after just a few weeks), but the static weights on the replacement ball somehow let me get away with that layout without the x-hole, but just barely.

And sanding the Special Agent would imitate the earlier read, but also would reduce the backend and make it prone to leaving corner pins.