I spend more than 7 days there, I see a lot of people say they would only want a day there and then back to niseko. Those people baffle me but each to their own. There is more off piste terrain than you can discover in 7 days at rusutsu, those who get bored simply arent finding the goodness in my opinion.
In saying that you probably should just stay at niseko ;-)
Ps a few of the boys on this forum are organising an informal meetup for the first week of feb at rusutsu if you are interested.
Sounds good ETM, I am aways exploring trying to find fresh powder! I have to cordinate my travel dates with another mate and both our jobs, last time we were there for the last week of Jan. So it may work out, I'll let you know if it does.