well i suck at the game, and i personally love the extreme tracks (aside from the last new one which is currently making my blood boil)
this dlc was well worth 400 points, thats 10 points per track, the achievements from it are nice too, a little challenge involved, not like the last dlc.
the tracks all seem a fraction harder than the originals / first dlc tracks, but i think when the correct lines have been mastered these will be just as 'fast' as the originals
my only gripes with the game are
-brake / reverse on same button, meaning if you're a bit slow like me, you'll start to reverse into the pit you just cleared
-no ability to watch a friend play (not talking replay's, though saving & sharing replay's would be a nice feature. just joining their session and watching how they do each section, my cousin and i both get similar times, but in totally different ways, combined, we would make a half decent trials player)