Sure it will. I owned one for 10 years and stayed aboard for sometimes weeks at a time. You can stretch out on the starboard side berth unless your as tall as Magic Johnson. I'm 5' 11" and I was comfortable. Directly above the stbd berth, a bunk folds out and straps are provided to secure it in the "down" position.
Perspective and personal tastes are important here. If your expectations are more in line with staying at a Marriott or the amenities provided by a large cruiser, then the Gulfstream will fall short. If, on the other hand, you treat it as a "getaway camping experience," it'll do the job.
Pack light, and minimize luggage. It'll take up valuable room below. Yes, you can store it on deck under the hardtop unless it's blowing rain-then the weather canvas has to go up to keep it dry.
You will not have shorepower, therefore no heat or A/C. I hear of some rigging a portable A/C unit as an aftermarket add-on, but that sounds like a huge hassle to me. Depending on the climate where you boat that may or may not matter.
Bottom Line: Yes, it can easily be done.