I put in RaceTech .90kg springs at the same time and had been running those for the last few months. Last night, I put the stock springs and spacers back in and I'm even happier. The heavier RaceTech springs were nice and sporty, but for my normal commute I think the stock springs are going to work better for me - just a little bit softer.
I'd love to ride mine back to back with someone with RaceTech or Cogent valves to compare. I think it's a huge improvement, but it'd be interesting to compare the three.