I like this place. In the spring. The road up is not where I'd want to be mid-winter, as it is steep, tight and closes when it dumps snow. The place is basically a big park, with lots of tables, table-tops, boxes, rail, pipes, kickers and hips. Fun when you are out on a jib board for a sunny day. There are definitely some areas that boarders will have to skate, notably just before returning to the quad
I went during New Year's week 07 and it was still crowded even though most people should have been returning to work on a work day.
The park was very small and they only had three lifts. At certain places the course was a narrow flat strip of 3 meters for about 100 meters and if you didn't have speed you were stuck. If you were a beginner this place really isn't for you.
Snow Wave Park Shiratori Kogen review by topherwillis
If you like rails and boxes this might be a fun place.
There are so many flat areas that you can stuck in if you don't keep up your speed. I would only recomend it if you wanted to play in the park. The halfpipes were not open when I went, but it looks nice and long so you can get a few nice launches, if the transition is up to par.