phenrichs, I ride a 2004 GL1800 and enjoy it as I have put over 120,000 miles on it. I realize this is very low mileage compared to many.
As far as reliability the GL1800 is a fantastic motorcycle, however it does have its unique problems. The seating position is just not comfortable for some folks, when I got my first 02 GL1800 I really did not like the seating position. It took me about 1000 miles to adjust to it and to learn to like it. Now it is natural. If I had done a test ride before that purchase I would not have bought. But the circumstances were unique and I bought it.
Also taller folks or perhaps long legged folks have a problem with their knees hitting the fairing. Folks have spent thousands of dollars to fix this and make the Wing comfortable to them---I would have just gone for another motorcycle. I am fortunate, I fit my GL1800.
Many folks wish the Wing had a sixth gear for cruising at interstate speeds. This probably would be okay but I have no complaints. This bike has plenty of torque and power when needed. And my average gas mileage is around 40/41MPG but this does drop quickly if your cruising speed is above 3000 RPMs. But it is still in the high 30's.
Many folks are moving to the Bluetooth connections for their helmets and I understand about the wires, however I have no problem with the wires on my Wing. I do have the top of the line J&M headsets with the upper cord and lower cord which you can easily pull apart and always leave the lower cord attached to the bike. I am sure that someday the Bluetooth type system will be standard but till then I will survive with wires.
The recalls have been well documented even the new brake recall that is noted in the above post. The seller should have this info available for you.
I have been very happy with both of my GL1800's and really enjoy riding them on the back roads or the interstate. This bike is great in the mountains on the twisty roads. I normally tow a trailer when travelling and have not had any problems other than an electrical issue that was easily resolved.
When purchasing put the pressuer on the seller for the owners manual and then read the manual. I would also urge you to get the factory service manual. They can be downloaded from this site or purchased directly from:
http://www.helminc.com/
You can also get some dealers to order them and might get a better price that way.
Remember this bike can have ABS and that is great if you happen to find one. The brake system on all GL1800's is linked so you do have to follow certain directions when bleeding the brakes. But the brakes are excellent.
I wish you the best in your search and if I can help in any way please PM me and we can get to a telephone or email.