I think you meant "Vulcan 2000" without the "Voyager" qualifier, right? The Voyager is one of the 1700 models Kawasaki currently manufacturers. Also, when you say 1700, you need to distinguish between the Classic, Nomad (both discontinued), and the Voyager and Vaquero, which are still made. All are different versions of the 1700.
I have about 10 days on a 2011 Nomad, which is a 1700 that Kawasaki stopped making in 2014. It has hard bags and a windshield. By comparison, the Vaquero (still made) has hard bags and a fairing, and the Voyager (still made) has hard bags, a fairing, and a trunk. New leftover Nomads are still around. I am really happy with mine.
Everything I've read suggests that the 1700 series bikes are a bit more comfortable than the 2000, as they have dual shocks, while the 2000 has a monoshock. I also have a 900, which is essentially the same frame as the 2000 but with a smaller engine. My Nomad was quite a bit more comfortable than my 900 on the two longish rides I've done (150 and 250 miles). I'd almost go as far as to call the 1700 ride "plush." I've never ridden a 2000, but I would assume it rides more like the 900. You might want that stiffer ride for local riding, but perhaps not for touring. So far I'm amazed by how well my Nomad handles while providing such comfortable ride.
People rave about the 2000 engine --- big, powerful, lotsa grunt. While the 1700 is a bit smaller, it's a lot more powerful than my 900, especially at higher speeds. It's also geared for touring, with a 6th gear overdrive that is really nice above 60 or so. I think the 2000 is a five speed.
Others with experience with the 2000 will chime in and correct any mis-representations I might have made. My sense is that the 1700 series is probably better for touring, but I'll let the 2000 owners speak to that.
Good luck with your search.