Speaking from the competition's view, GLF has turned the design characteristics of the "legacy" fuselage into a marketing angle with the aft galley. The fuse has a large section aft of the cabin without windows and the engine location within the rotor burst zone makes an aft galley attractive, if a dark "cave". It also locates the heaviest item of cabin furnishing aft, avoiding a forward CofG's decrement to cruise drag, hence range.
The GLF's section with the highest decibel count is also aft, the aft galley keeps the passengers forward, in a quieter zone. The Global's quietest zone is the aft area making it an ideal spot for sleeping. It's four or five decibels quieter than the GLF due area ruling the tail and the further aft engine mounting.
F/As seem to like one or the other, depending on experience. The inter-cabin door frequently needs to closed with a forward galley, as food prep, cleanup is in view of the pax, including the inevitable messes. Boarding stores is easier with the forward arrangement, as is trash removal. Esp, when forgotten in the air stairs behind the curtain.
All that said, there are trade-offs inherent in any design.
GF
EDIT: You have a shower? How's that fit in the GLF?