I've been looking into the Singlecross lately for the same reason; dirt and mods in the high chain, compression in the low.
How do you blend the signals back together again? (assuming you don't bi-amp)
Any phase issues? Hollow mids?
I plan to buy the Singlecross and do exactly what you speak of: compression (and octaver) for the lows and dirts for the highs. I plan to do the blending (if needed) via the "merge" function on my Radial JDI…