Good timing! I played through Trials Evolution Gold today and Urban Trials Freestyle. The core stuff in trials is good, but I think Evolution really showed there's not much more you can really take it further. Evolution had some additions, but mostly it was just Trials HD with fancier graphics and I think most people can agree the graphics don't matter at all in a game like this. I know they're continually pushing new multiplayer modes but I only got a chance to play Evolution single player as no one's playing it anymore.
I think Trials HD was a game of its time. When X360 first came out and there wasn't much to play it was a fantastic and addictive leaderboard game that ALL your X360 friends were playing because there wasn't much out and it had good word of mouth. So you'd been continually competing against the ghost riders of a whole ton of people you know and it made it really exciting and fun. Playing Evolution today lacks all that and it's just kind of "fun, but more of the same and it's getting a bit old". Can't see Fusion doing much to change that core problem.
Urban Trials was ok and at least has a little something going by being portable Trials as Trials is a perfect "pick up for 2 mins" game for mobile gaming with actual controls. Also kind of surprised me how playable Trials was at a shitty <25fps that the Vita game runs at. Didn't affect the gameplay much.