Season 10 was the beginning of the end for the show. Stories not so much about the supporting cast as it was about Steve McGarrett. Also this was the beginning of filming in Hawaii and California, which I think lowered the shows quality. I grew up in Hawaii and will watch, but you haven't seen this season, its not the best of the series.
Update: When I originally wrote the review I had seen on 3 discs. The third disc was better than one and two but the fourth and fifth discs were much, much better! A bit disappointed overall but the last discs are worth it. Sorry Steve!