I'm also interested in hearing @datsvechkin's thoughts on Sprungs vs. the R1. I'll provide my general impressions as I have also used both. I've used Sprungs for well over a decade, most recently with Easton Mako M7s. I've only skated R1's twice that are on True TF9 boots - I hope to give these a better work out and play some pickup games soon, but my general impressions after briefly using both back to back were:
The R1 was a bit heavier and I could tell the difference when I wore the two skates back to back.
The Sprungs felt a little more mobile and I had better control for turns and stops, but the R1 is still good for turns and stops and is better than a flat chassis.
The R1 and Sprungs both allow for a full stride extension unlike a more traditional flat chassis
The movement in the R1 was less noticeable than with Sprungs (that's also comparing new R1's to used Sprungs though)
The R1's had a more robust and solid feel - I think they'll hold up better long term.
So far, I like the Sprung feel a little more, however; I still liked the R1 much better than from what I recall of using an older flat chassis or the ancient Tuuk Rocker. An alloy version of the Sprungs would be ideal, but I don't know if the planned Fizix frames will ever happen since the FB page hasn't been updated in almost a year. With that said, I think the R1's are the best current alternative to Sprungs and seem like they'll be more durable (it's hard to be sure as I've only skated twice on them and I did read about people that had some issues with the early versions of the plastic portion. Apparently, they've reformulated the plastic resin to eliminate those issues and they did take care of the people that had breakage issues). I definitely prefer the R1 to any of the non-Sprung alternatives. Keep in mind, this is only my initial impression after only two light skates with the R1.
What I'm thinking of trying to do is go to a couple pickup sessions with both skates and switching skates part way through. Getting a feel for both back to back during game play will give me a better idea of how they compare.