Don's hub, along with all the stuff he makes, is excellent. I did my modification thinking I could have all the improvements that Don's parts would give me for about half the price. As it turned out, my machine work costs quickly made my costs more expensive and I don't think I saved a dime especially since I spent a lot of time doing research, making parts, and running around to the machinist. I certainly wouldn't bother to adapt a hub to a commando that was a "spoke hub" since Don's parts are available and beautifully made.
Wtbs, I have a rear sprocket that I can change without removing the wheel. I can change it's size, which you can't do on your stock norton parts. I use a tubeless tire, and I would bet that my cast wheel is more rigid than a spoked aluminum wheel. As far as irreversable goes, I saved all my stock parts and actually bought a second swingarm to modify to accept the cast wheel, so my modification is easily reversed if I wanted to do that.
As far as looking like a norton goes, you got me on that one, but I'm in good company with the many beautifully modified commando's out there that aren't "stock", including Don Pender, Jim Comstock, Yves, and a long list of fantastic Commando based specials. For more than 40 years, I've had fenders painted to match the tank and side covers. It's so "not stock", but I liked the look better than chrome. I love that CNW paints their fenders. I think it makes their bikes look better than gawdy stock chrome fenders. It's nice to see that all these high quality nortonistas aren't limiting themselves to "stock" applications.