I had a chance to play Whiteout last night and it wasn't too bad, Reminds me a bit of Genesis with the base layout and side routes and a bit of Nivo/Frosty. I think a few areas of the terrain (mainly the center) would benefit from a little smoothing, some of the smaller slopes that lead right into another slope are just a little too steep to not take damage from no matter how you approach them. The side routes i played with where pretty fun and quick so the gameplay on the map was pretty fast paced and since it's a pretty small map i didn't see much rabbiting so + to that.
Still have not seen Catwalks and i really wanted to try that one just because the shot of it in the blog looks really awesome, but like usual the map rotation was SleepWalker/Moonshie/SleepWalker/Nivo/SleepWalker
The only problems i see with both maps are the generic frosty bases that every map uses, it gets boring quick.