I owned a 2010 Nomad. I liked the bike, and it did make for a very good touring bike. However, it felt like the gearing was off, like it lacked in the mid range, and there was no power in 6th gear, but it was smooth. It is my understanding that beginning with the '11 models, the mid range gearing was changed to give it a bit stronger acceleration. I also believe that starting in '11, the KAMS mod was included as was the computer update to prevent engine dying at an idle.
As for how it is as a touring bike, I found the Nomad to be a good long distance mount. It is comfortable and decently smooth. Gas mileage could be better, but unless towing a camper trailer (something I don't recommend) it routinely got me about 40 mpg. The included hard bags are specious, and if you add an aftermarket top box, you storage space should be equivalent to that of the Voyager. What you will lack is a sound system, but that is something easily added at reasonable expense. It may not even matter to you. Many riders just prefer to plug earbuds into an IPod or other music device. I think external speakers are a waste, as over about 50 mph the sound is lost to the wind, anyway.
There is no way to get around the heat generated by the engine and exhaust headers. By the nature of the Vee Twin engine design, you are going to get a lot of heat. While Kawasaki tells us that the engine is liquid cooled, just remember that only the top end is. The rest just puts out lots of heat, which is noticeable when it gets hot out.
If the bike you end up with doesn't have crash bars, seriously consider installing a set, both for the obvious reason, and for adding a set of footpegs so you can stretch out your legs on a long ride. You may also want to add a set of wind deflectors that attach to the upper fork guards/tubes, depending on how annoyed you are with the amount of wind you experience coming up from that area.
Overall, were I to consider getting another cruiser, the Nomad would be near the top, if not at the top, of my bucket list. But I wouldn't consider one older than an '11 model. I also think that the Nomad is everybit as good a tourer as the Voyager. It just doesn't have the full fairing, fairing lowers and a trunk. I can live without all those things. Others feel they need the full-boat touring package.