Without going into the details of the allocations, I will just point you to the following thread, which you may find familiar - http://lavag.org/topic/15354-testing-for-the-same-class/
And note that regardless of AQ's performance trick (which can be found at http://lavag.org/topic/15135-performance-tweak-for-lv-classes-and-to-more-specific-node/ ), using the default value of the class there was more efficient. I don't know if that changed in 2012.