Played most of the packaged kevlars (with the included syngut crosses). My favorite setup was Crossfire mains with ToughGut crosses. Definitely more comfortable, better feel, and more spin - as well as more money. It lasted me as my primary racket almost a whole summer, though, so it is cost effective.
Tried poly crosses (think it was SPPP) with kevlar mains from ThinBlend. Definitely different, got excellent spin, but never really got the feel of what I needed to do to put the ball where I wanted it. I cut it out because it was too tough on my arm.
I suggest the 18g Crossfire kevlar with the ToughGut mains.