I have two, a 1980 CX500 Deluxe with a Vetter fairing, and a 1983 CX650 Custom, These are 4 valve short stroke water cooled transverse flying V engines, they love high rpms but the bikes them selves need better front brakes, the US bikes are single disc front, drum rear. They use driveshafts. The CX650 is the one you want, has electric fan, slightly higher gear ratio, lighter bike. They have a notorious problem with the stators burning out, you have to remove engine, which is actually easy, i did it to the 500. And the water pump seals go bad.
The turbo version is wicked fast, the GL versions are like small Goldwings.
Carbs can be finicky to balance and you will notice it. If they are out of sync its like holding a pair of chainsaws.
Go drop in at the cx500 forums, the cx500 was my first motorcycle. I wish they would come back as a V4, would be superior to our Yamaha Vmax engine.