I have both right now. Did a lot of miles on a Savior from 78 to 82, it was pretty good, but not as good as a swingarm. Unfortunately the Savior I have now had a lot of plate welded in on the rear portion from oil tank to plunger, and was removed badly, tubing is a bit messy.
A swingarm is more tuneable , easy to change things. When I bought my Savior it was a choice between it and the Santee swingarm one. Also the challenge of mid ring the team sounds appealing to me.. have or create something different. AND HAVE A custom framed bike that can do a 800 mile day..