Schwalbe kevlar TT are almost a full pound lighter than k-rads. I put them on for a brief period but did not like the way the tire rotational/gyroscopic feel changed. I put the k-rads back on. But that is just me.
my favorite set ups are:
fs100 or kiniptions for pure park
fs100 w/ a front table top kevlar for street/park/dirt
dual table tops for all around
dual holly rollers for awesome drifts on anything
hookworms for hucking gnar stairs