I've said this before one of the original bionic vs atrix (or vs tbolt or just bionic threads i dont remember), that a dual core phone as of now is an investment, with the payoff coming 6 to 8 months down the road.
Don't disagree, but I've seen several videos now where rendering and browsing is a significant and noticeable difference. The way people complain about lag around here it certainly seems like they are rationalizing going with the TBolt.
To be fair, I don't think we've seen this comparison between the Atrix or Optimum 2X and the TBolt, but even if the TBolt lands in the middle it would still be a pretty noticeable difference.