I only bought Cruis'n so far, but it's quite a let down.
Races max out at a minute and a half, some are over in under 45 seconds. I'm never one to complain about rubber banding, as it's an essential part of what makes arcade racers fun, but with that, you also need game mechanics that make it at least feel like you're in control of where you'll place. In this game, nothing matters. Boosts do barely anything, tricks do barely anything, drifts do barely anything, it really feels like you can hit everything perfectly or hit absolutely nothing at all and the result could be the same. There's not even an illusion of achieving something here.
So my vote goes to Hot Wheels even though I've yet to play it, as I cannot imagine it being more shallow than Cruis'n Blast.