Even though I wouldn't say no to a higher exp bonus (lol who would ^^), I still do high level roulette everyday because while mobs don't give exp, all the instances are heavily outgeared (even if synced down to i110) and are basically a 15 minute speedrun. It's true the 3.0 dungeons give more exp, but it usually takes a good bit longer to clear them, especially if you kill every mob.