I'd be interested in hearing feedback on this as well, since I'm debating repair-replace options.
My understanding is that Progressive no longer sells a non-airshock OEM length replacement for the Valk - is that correct? It's also my impression from what I've read here that the Progressives WILL eventually start to leak.
I've only heard vague, but very positive things about the Works shocks - but nothing specific, and nothing about longevity or specifics on ride quality/improvement.
I've also heard that the interstate shocks work well on a STD or Tourer, but am under the impression that is to account for heavier loads on the bike.
My thought is that I don't mind paying a small premium for Progressive if the ride is substantially better than OEM and they'll be supported in the long run, and I don't mind paying a large premium for Works if the ride is the same or better than Progressive/OEM/Interstate, and the shocks will last the lifetime of the bike (which I hope to be many more 10's of years).
For background I've got a 97 STD with OEM shocks, looks like the upper bushings are starting to fail, the markings are worn off so adjustment isn't a simple read and turn, and my lower dust cover on one side has broken free and rattles every time I hit a bump. The ride is very stiff with 1 (200# load) or 2 (320# total load)

up, however I've not tinkered with the adjustment of the OEM's yet (haven't hit my 1 year anniversary with the bike yet).