I didn't like the ride of the newer Wings, too smooth, you're up into HTA territory quickly without realizing it, like a Cadillac.
When I went to a GL1200 from a Sportster I just about lost it in a corner. The Sporty vibes let you know how fast you were going. Goldie didn't and I was going in fast.
The 1200 had the stator issue and was the reason I sold mine. It isn't something you can change at the side of the road and output was weak. My issue was actually several failed reg / rectifiers.
I went from the GL1200 to a 1000cc Connie but didn't like the Connie Buzz or top heavy handling. Otherwise it was a good bike.
In 2008 when the dollar was over par I bought a mint low miles 1998 GL1500 from the states for $8000 USD. It was a super deal and there should be better ones now. There were no recalls to deal with on the paperwork.
In 1997 the GL1500 got the more rugged Valkerie transmission.
There have been minor changes along the time line. Early models had Japanese alternators but the newer ones are Chinese and have a slightly higher fail rates. Aftermarket alternators are available and easy to change.
Production of the GL1500s ended in 2000 so even the early GL1800s are 15 years old and coming down in price if you shop in the USA. Having to add 30% to the dollar hurts that.
GL1500s are durable even with just modest maintenance but the older ones will have had numerous owners with their own ideas on add-ons.
The 1500 is roomier than the 1800 but heavier.
Max rider / passenger weight is in the 425 -450 lb range IIRC and if you go to a Goldwing rally you will see that totally ignored plus they haul a trailer.