I have a small Alps tour business where I get to ride new rental bikes every year including Hondas, BMWs, Aprilias and KTMs. Riding here at home is about 20% of my annual riding and I look to own nice used sport touring bikes that can enjoy solo and can also be comfortable 2-up when my wife wants to come along.
I owned a 1992 ST1100 for 6 years or so. I added a Laminar Windshield/Lip combo, bar risers, RLD seat, wind deflectors, upgraded suspension, upgraded front brakes and several other farkles. I enjoyed it solo and 2-up.
In 2019 I purchased a 2008 ST1300 ABS. The bike was in great condition and came with the OEM wind deflector kit, OEM top case and bar risers. I added Sargent seats, upgraded suspension front and rear and lower rear pegs for the wife. It handled better, braked better and was faster than the 1100. We were also pretty comfortable on it - my wife liked the lower pegs/OEM backrest on the top case. I also liked the adjustable windshield.
While I liked the 1300 quite a bit, I had 2 big issues with it. It threw off a LOT of heat - the hottest bike I have ever owned or ridden. Riding in temps over 75F was noticeably warm, riding in 80 - 85F was toasty and above that I was sweating. I tried the mechanical things like syncing the throttle bodies, cooler plugs, cleaner air filter, different oil, etc. - no significant difference. I cut down the windshield, removed the front cowls and added Baker Air Wings and all of those things made a noticeable improvement - as long as I was moving at a decent clip. I suspect my 1300 was an outlier as to the excessive heat. The other issue I had with the 1300 was that I found it to be quite top heavy, especially with a full tank of gas, full luggage and my wife on the back. I had to be very careful in stop and go traffic, pulling into gas stations, stores, parking etc. That top heavy nature was also something I had to pay close attention to when pushing it around the garage.
In September 2021 I flew down to Lancaster PA and purchased a 2018 Goldwing Tour 6spd manual and then took 2 days to ride it home to NH. I have to say it is probably one of the nicest bikes I have ever ridden and certainly the best motorcycle I have owned (it should be for the money). There is no engine heat to deal with. The weight of the bike is all down low, which makes the bike very well balanced. I just turned 72 y/o and while the 1800 carries more pounds than the 1300 did I find it less precarious and easier to push around the garage (and get on the center stand).
Everything about the 1800 feels more refined than the 1300, as perhaps it should being 10 years newer. The clutch pull is easier, the brakes work better, the engine is smoother, the transmission shifts easier, etc. I test rode the 2017 Goldwing and the 2017 Goldwing F6B bagger (which I preferred) but both were too big and too heavy for my taste. I would describe my 2018 Goldwing as a cross between the ST1300 and the previous generation (2017 and earlier Goldwings). It's smaller and lighter than the older GWs but with all of the GW goodness in the engine and comfort areas, maybe 80% GW and 20% ST. I find mine handles nearly as well as my 1300 (I did a track day this past August on the GW, which got me more comfortable with the bike and its limits). The weather protection is similar to the 1300. I also feel the GW has just enough tech with the electronic preload settings and ride modes to be useful along with things like GPS, etc.
As someone posted earlier the 2018 is the first bike I have owned that does not require a lot of modifications to ride comfortably for long periods. I would also agree that is perhaps more of a ST1800 than the earlier Goldwings. I am perfectly fine with that.