This was my first time at Biwako Valley. I had very low expectations based on some of the other reviews but was pleasantly surprised. I did a bus tour from shin osaka that cost 6000 yen for the bus and the lift ticket, which I thought was a pretty good deal overall (depending on day, cost is 5000-9000 yen, and there are also pick ups from 5 spots in Kyoto and Osaka).
On the plus side, the views were amazing and the snow was much better than I expected. The crowds weren't too bad, although this was a sort of family holiday in Japan, so they might be worse on a more typical weekend.
They had a small terrain park with a few big jumps and a rail, but otherwise the mountain maxes out at beginner/intermediate. The bus only took about 1 1/4 hrs to get there from shin osaka, so I was on the slopes by 930, but the return took about twice that due to heavier traffic.
As noted, there are only 3-4 longer trails and they were all closed that day, which was a bummer. As it was, all my runs were less than 3 minutes, but the lines at the chair moved quick, so i got a lot of them in. If those longer runs are open, I think you might not get bored as quickly.
Overall, I had a surprisingly good day on the slopes of Biwako Valley. I would say if you want something close to Osaka/Kyoto for a day, this is a solid one-day option. The views of the lake would impress anybody, and I think it would be particularly good mountain if you have kids or are with a beginner, or perhaps if you want to use your first day of the season to practice and loosen up before going on a multi-day trip (which is what I did).
From 03 January, 2011
Snow condition on visit:
Soft, and clumpy but not too sticky. Nice
Things I liked:
Good snow, awesome views, close to Osaka/Kyoto
Things I didn't like:
Only a couple longer trails and those were closed.