I had a 1992 VT1100C Shadow. I put well over 300,000 KM/185,000 miles on it. I literally, not figuratively, rode it all over North America.
Failures were one fork seal (I replaced both), one shifter shaft seal, one front wheel bearing, one light bulb.
It consistently returned 60 miles per imperial gallon, 50 miles per US gallon.
My only complaint about it was the four speed transmission. There was a huge change in ratio between third and fourth. It could become irritating when traveling in circumstances that required being in the 45 to 55 mph range while dealing with climbing elevation, riding the Blue Ridge Parkway being a good example. In third gear at 50 Mph the 1100cc V Twin engine would be revving to high for cruising comfort. Not high enough to hurt the engine, it was just irritating. In fourth gear under those same circumstances the engine would lug to much when trying to climb a hill a decent grade. The result was that I was constantly shifting between third and fourth under those conditions. Since I seek out those types of roads, this was often the situation. If those same conditions allowed maintaining over 60 Mph there was no problem in fourth gear. Later on in the Shadow line they changed to a five speed transmission. I was told that the fifth gear was the same ratio as the old fourth gear, they just added another gear between third and fourth. I don't know what model or year that was.
Pre 87 and the 87 model onward were quite different visually. I don't know about the technical changes. I also don't know what changes happened, or when they happened, between the 87 and my 92. I do know that the 92 had wider handle bars, which was a big improvement, and different carburetor jetting which gave the 92 a little more power.
Mine was pretty much bullet proof. Maintenance was real easy. Hydraulic valves are great. Oil changes are simple as could be.