MUD isn't bad at all, I'd say it's the best Vita game from them that I've played. The graphics are dire, but the music is there (stereotypical rock/metal tracks) and it really reminds me of the old Tony Hawk era games.
It handles well, runs smoothly and has a full career mode though :D You can also get it pretty cheap, I paid £12 for it a good while ago. (I got WRC3 at the same time for the same price).
May well be worth holding out for their new MX game now though, as MUD was also an officially licensed MX game. Did you ever manage to get Moto GP? I've seen that it's really sim heavy, but damn I used to love the old Climax Moto GP games which were also pretty brutal. I have about £11 of credit with Shopto atm which means I could get Moto GP for under a tenner... maybe I'll treat myself when I get paid again haha.