I gave it a second thought after @ocnor comment...For the price of a sm57 and a nt2, you can get the mesa CabClone.
You can get descent to good result (I'm pretty sure one can) without any mic placement issue or room treatment issue.
I can see it as a good thing for most of home recordist.
According to my poor experience, I can imagine the Mesa CabClone beeing more helpful on distorted sound.
Ok, then you'll face some problems when recording some combo amp.
I'm sure I can get descent sounds out of the mics too with some precautions and with some room sound deadening....
Last question, is the Mesa CabClone better than an amp Sim? Well I don't think it is. It's just a good way of not, or less, frustrate a guitarist that has spent 2000$ in a amp head.
I'm also pretty sure that there are better option than the Mesa CabClone...the Koch loadbox seems to be one.