I had a 55-105 set sitting around for a couple years... put it on a few times, but I was usually back to my LaBellas or Sadowskys by the end of the day – never really did much for me. Then the other day, I decided to give them another try out of the blue. Spent an hour+ dialing in a full proper setup, which I never quite did any of the other times I had them on... huge difference! This is probably the lowest action and neck relief I've ever achieved, thanks in part I'm sure, to the higher tension.
The increased tension on the treble strings makes for a whole new playing experience... I tend to do a lot of JPJ-style 1-5-1/power chord stuff, and I find that the added stiffness in the D and G gives me way more control and articulation when raking across three strings.
The tone is pretty sweet so far... next to DRs, they're probably the most broken-in sounding flats I've used. Huge bottom end with a pleasant, understated crunch in the highs/high mids that cuts through juuuust enough. The Sadowsky Black Labels I'd had on previously had a massive, growling mid-range presence that I loved, and yet somehow I don't find myself missing it.
Paint me impressed!