That one is the cruiser or "C" version. Smaller, more sloped tank. The standard version has the bulkier, more flat-topped tank. Then there was the "Silver Wing" model, kind of a light-weight GoldWing. Those came either naked, or with a full fairing and there were several combination options of hard bags and rear top boxes. The SilverWing, when equipped with the full fairing, also came with dual front disk brakes. It also came with single-shock ProLink rear end, which, as it happens, was one of the first, if not THE first, street application of single-shock rear suspension for Honda.
IMHO, those were/are great bikes! I had a C back in the day, and loved it. Plenty strong, good looking (again, just MHO) and the lightest clutch pull of any bike I've had before or since. Plus, nice clean shaft-drive! And, at that time, it was one of the smoooothest, most vibration-free bikes I'd ever ridden. And even then, a nice thumping V-twin bit of character.
Mine did have a water pump seal spring a leak, but there was a nice tell-tale drain hole to let you know. If you saw anti-freeze dripping from the weep hole, it meant a seal was going south. And, it IS true that the whole engine needed to be dropped to replace that seal, but I did it by myself in one Saturday with nothing more than "normal" hand tools. Once all the accessories were stripped, the motor fell right out, the seal popped out/in, and right back together again.
I disagree on the "built for turbo" deal. The CX500 debuted in 1978, along with the CBX. In those years, Honda was getting a bit of a reputation for building "bland", not-quite-cutting-edge bikes (other than perhaps the GL1000), and the CX and CBX were intended partly to counteract that idea. They had pulled out of GP racing some 10 years prior, and were cranking out the 750 & 550s by the thousands - nothing that could be cutting-edge by then...
The turbo didn't come out 'till '82 - WELL after the initial design/intro in '78.
So, can you tell I'm still partial to the CX's...