Suntour Superbe Tech was actually a fantastic derailleur, even though there are write ups about how bad they were, not sure where that stuff comes from because I used one for over 150,000 MILES and never had one problem, I have another bike with the Tech on it as well and it has maybe 25,000 miles on it with no problems.
When the Tech is set up correctly that thing will shift fast and smooth, plus it will shift with a load on the cranks like when going up hill and you need to shift enabling you to do so without have to reduce pedal pressure. Mountech was built the same way and I used one of those on my former touring bike with no problems either, in fact I loved it for touring due to its fast and sure shifting.
I am pretty meticulous about keeping my gear clean so my Tech and Mountech derailleurs lasting a long time might have something to do with keeping those derailleurs clean? Water doesn't seem to do bother those either.