Never heard of a 360 Cat engine. I believe Cummins has a ISC 360 hp engine, but the Caterpillar engines C-7 were 350 hp.
As far as Gulf Stream coaches they are like any other coach. You can buy entry level and you can buy top end. I happen to have the top end Gulf Stream and I could not ask for a better coach. Cabinets are solid walnut, not particle like some one posted.
I do agree that customer service is bad because they do not manufacture motorized coaches anymore.
Gulf Stream also used to use a lot of Mercedes engines on their TourMaster coaches which were very good engines also. You do not mention which Gulf Stream you are talking about. Some entry levels might be made cheap, but their flag ship coaches were just as good as any 300K dollar coach.
Lot of bad information has been issued out by some posters. The thing is they do not know anything about these coaches. All it takes is one bad apple.