This is a good place to improve your technique if you are a goodish boarder. However, if you are high pushing on expert then you will probably manage to ride every run within half a day, no matter how big they say the place is. The only bonus will come from really easily available powder. Of course this is generally off piste so at your own risk.
If you are still beginning then you are likely to find this a hard days work, with all the beginner slopes rammed and transisitions betweens slopes filled with little hazards require technique, like skating and sliding on virtually flat ground.
The lifts which after the snow and slopes are the most important things are seriously lacking. They don't offer anywhere near good coverage of the slopes. They are awkardly placed requiring awesome skill, or a whole lot of skating, not something i want to do. The other facilities were sparse but I think that really if the boarding is amazing nothing else matters.
Really this is a place not realising it's full potential. With so much space and so much snow they should redevelop it and turn it into the premier snow place in hiroshima. The potential is there.