I don't have a cable shift setup. I have the S2 type linkage that Richard (at Banks Service Station) provided with my NG3. I've considered converting but I really don't have a problem with what I have. Other than SwiftDB4, I don't think I've heard anything negative about them. That could be because of the particular design of SwiftDB4 or the fact that the owner had put a lot of work into it and wanted to believe his work was justified or they really are much better. Don't misunderstand - I am not down on them. I don't really have an opinion other than I think they're cleaver and in some cars, it probably makes more sense because they are easier to route than a rigid shift linkage.
I scanned Grumblebun's links and the last one suggested using Morse cables. They are pretty easy to get at boat shops but in my experience Cablecraft (
https://cablecraft.com/home/control-cables/cablecraft-motion-control-cables-overview/cables/push-pull-control-cables/) makes much better push-pull cables. When I was racing a lot of guys used Morse cables for adjustable anti-roll bars or throttle linkage. Carroll Smith in
Prepare to Win recommended Cablecraft cables so I got one for the throttle cable of my race car. I liked it so much (it seemed more solid than the usual accelerator cable but maybe I was justifying my purchase!), when I built my Europa, I replaced both the throttle and clutch cables with Cablecraft cables. They are much more flexible, can make much tighter bends, and they seemed much smoother than the Morse cables I checked back in the day. If you do implement a cable shift setup, I would recommend using Cablecraft cables.