I got it Thursday and just..wow. It's so good, I'd go as far as to say best Wii U game yet (well until Smash). I'm really happy the bikes have been balanced as they were really unfair in Wii and they spoilt online. And I'm glad all the features from 7 (vehicle customisation, water/gliders) are back because they add to the game a lot. Antigravity is great new mechanic too,the fact you get a boost from hitting people suits my kinda-violent racing style
Battle mode sucks but eh, not that fussed. If I really have to play battle I'll just pull out Double Dash or something.
Oh, and I so want that Japanese Merc DLC: