Rocker, I too have wondered about a 750 NTX. Although the newest version of the 750 only cranks out 51 hp it appears to be coupled with enough torque (42.8 ft lbs @ 5K rpm) to be a really fun bike. After all, my G650GS only puts out 50 hp and it does OK both on the highway and on mild off road stuff. The thumper is buzzy on the highway so I hesitate to take it for many 400 mile days. A mini-NTX, on the other hand, would have the smoothness of a Guzzi with at least as much torque as the thumper. I just wonder about the weight of this package, as well as how to make it cost competitive. The competition is getting pretty tough in the 700-800 cc adventure market. For $10K or less you have choices from Honda, BMW, Triumph, and others. They all weigh between 426 lbs and 502 lbs (Cycle World, Dec 2012) so the NTX should be no more than 500 lbs. without bags to be competitive. The new V7 Racer has a MSRP of $9990 so I'm guessing the NTX might be about the same price with less bling and without hard bags. Still, that's at the high end of weight and price for the market.
The current NTX is successful by making a complete bike (lots of things one would normally have to add via the options list, like crash bars, hard bags, driving lights, etc) at a price point that beats the competition. What I'm saying is that the 750 version really ought to do the same thing in the smaller capacity version but I can't see how the company can shave 125 lbs and $6K off by using the smaller engine and a slightly lighter frame. I'd like to hear other opinions.
Growing old ain't for sissies!