Well the appeal of the loft is being able to contain all of the office sprawl to a single spot, possibly making this the day job spot. Plus being able to toss offending objects (or toys that want to go "Whee!" over the side to land below.)

In the other layout, the kitchen/great room arrangement is nicer, but the desk would have to go in either the alcove (facing a wall) or a setup in the master bedroom.

Not that I've given this a ton of thought.... :-)