I replaced one of my S1's with a Timney. The other S1 has the original trigger that was worked over by a friend of mine. There are a few youtube videos out there on how to get the most out of your factory trigger. My S2 has an adjustable 2 stage trigger that is not that bad.
I worked my S1 trigger myself by reading a few articles on the subject. It was about 5lbs after adjusting the so called "trigger weight" screw, before adjustment...5lbs.. after adjustment...5lbs. So i worked it over, now its 2.5lbs with a little creep but a 100% improvement over stock.
I've got several Vanguards. Generally I have about 50% success in getting them to improve using Kiwi Nate's instructions on this forum.
My last one I removed about half a coil from the trigger spring and that was almost too much. So, consider taking off even less if you need to. I only removed a bit of spring AFTER tweaking it first and not getting improvement. That's the first one I have tried that with, and it did help.
However, I own both Rifle Basix and Timneys, and much prefer the Timney.