I've tried this Sunday to take advantage of the one-day trip offer with the Shinkansen to go for some snowboarding. I took the cheapest plan I could find, which was for Yuzawa Park (10,800yen including the lift tickets) \r\n\r\nIt is said "what you pay is what you get". This could be applied for Yuzawa Park.
The courses were really short, the longest lift is just 550m. If you actually tried to speed up a bit you would run out of course in less than a minute.
Another problem that I encountered was that there were many newbies, and although it was snowing all day, no fresh snow was gathered on the courses cause all the learners just kept on pushing it away by pointing the board vertical to the slope.
Things changed in the afternoon and during the night skiing. The courses emptied and new fresh snow started gathering. By 6 in the evening the snow conditions were very good with even some fresh powder gathering in some parts.
The night lights were open also in the advanced course, which also had a small artificial ramp that you could catch some air! In general during the afternoon I had fun, although I was a bit disappointed that the course was short (about 700m at its longest part).
Closing arguments: It is not a bad place to go for a one day trip but definitely not a place to stay there for 2-3 days.