In an absolute sense, the 84 is not overly fat. But in the hand, it does strike me as *relatively* fat for a such an otherwise trim, well-proportioned and beautiful design. It's not a huge issue, but I do notice it.
Most of this is due to the factory grips. The slim G10 grips from LOK transform the grip of the 84 to something that feels very close to perfect.
For me, anyway. Everyone has their own take. But if you end up with the 84 and find yourself thinking the grip seems fat, a very effective fix is available.