I couldn't get into the one from last gen. It was too serious or at least it presented itself that way. I I got it on day one and logged in probably less than two hours. I should give it another try.
You should definitely give it another try. I felt exactly the same at first - aesthetically it was just so disappointing coming from SSX3, and the Deadly Descents were a terrible gimmick (I didn't enjoy any of them).
But underneath it all, it's still SSX. It still controls fantastically like you'd expect it to, and once you complete the campaign you can play free ride on the good maps or do Global Events - which are like continuous multi-player events to set high scores, and I found that really engrossing.
Plus, the soundtrack is on point!
I'd now rate it among my favourite SSX titles, but I took quite a while to coming around to like it.