Overly-scripted and silly.
It's not that I particularly hate the scripted stuff, but it really rankles when they play it seriously and go into acting mode. Take Hammond's crash, for instance, when he decides to race back down the hill. He takes a corner and then out of shot we hear his car supposedly rolling over. Now, OK, doing it this way saves time and money (no stuntman needed, no mods to the car needed, no tricky choreographing of the 'crash') but please don't try and convince me it happened like you're making out.
For me, Top Gear is at it's best when the three of them are allowed to be themselves - the banter (I hate that word) and moments of genuine, unscripted humour and incidents - rather than the set pieces and acting.
Also, I don't know if this was just me who got this vibe, but their hearts didn't really seem in this opener.
Early days... Early days.