I just got the Kickr last night.
Going to swap the cassette as it was super noisy for me, my RD may be a little out of whack though, or just not a good match to my chain or something.
I rode it in sim mode with 100% difficulty this morning. The 10-15% stuff was hard but doable, just have to be ok with lower cadence. I dropped down to about 55 rpm to stay in Z2.
Power tracked pretty well with my Quarq, except for some reason on some of the steeper stuff the Kickr read 5-15w high, and on descents it read 5-15w low. I suspect if I put the difficulty back down to 50% it should track really close. Anything between was pretty much a wash between the trainer and the PM.
Looking forward to messing with ERG mode tomorrow