Just my opinion:
LC or
Sonus = Sonus hands down
Sonus DAS vs. SFX = Don't know, since I haven't tried the SFX, they are too new to know for sure.
Even though you could use the SFX pads with anything you want, the SFX pads were specifically designed for the SFX polishes. The DAS pads weren't designed for anything in particular orther than to be a step above the regular LC pads (which are still very good). I feel that the pad texture and overall construction is a grade better than the standard LC ones, and the SFX pads seem to be somewhere between the two, and again are only offering three pads vs. four.