I think the main problem with Sonic games is that try to be innovative and fail with it(Werehog in Sonic Unleashed).
Only if the quality came back to the series would the franchise be a hardware booster. I personally enjoyed Sonic Unleashed a lot though! With Mario games you have the main series platforming and you have spin-offs the difference between Mario, Sonic and Banjo is that Mario still sticks with its roots while getting different kind of games. Something both Sonic and Banjo franchise aren't doing~~
As for Banjo Rare got way ahead of themselves. They tried making Banjo and Kazooie into something it isn't. I loved Nuts and Bolts but for all I care they could have called it Captain Obvious and its new Mobile. The game is quite hardcore though something I didn't expect from it:P







