I had a 1990 GB CruiseMaster, for 9 years, traded on my present GeorgieBoy Landau, new in 2001. They are well made, reliable and have some good features. Both of my motorhomes have been relatively trouble free. (2000 Landau went back to the factory early on, great since then)
Mine also has a propane generator, it has worked well for us. During the summer we often run the genny all day on the road to use the roof AC's, or for a day or 2 at a dog show, propane is not hard to find and burns clean and is quiet. (Gas genny needs to be de-carboned periodically.Propane does not) However if you plan to boondock or live "off the grid" for extended periods your propane will only last for a few days constant use. In that case it is more convenient to have the genny run off the same fuel as the engine...
With any MH of that age, condition is important, good maintenance records, really check for water damage or delamination, a rubber roof is usually good for 12-15 years, belts, hoses and tires are good for 6-7 years tops.
The other three coaches you mention all have a very good reputation. If the GeorgieBoy was in the best condition of the 4 it should certainly be considered. Interior layout and how it fits your needs is a big factor...
Brochure on the 99 Cruisemaster is here:
Cruise Master by George Boy
Construction, Aluminum framing in sidewalls and roof, galvanized steel in below floor compartments.
Good luck ...