I first rode fixed on a taster session at the Manchester Velodrome, ans was still on a high when I got back home to Bristol several hours later. I've found that riding on the road has taken a lot more getting used to, but am pleased that I have persevered. Descending as a fixed novice can certainly be a bit hairy, as can those moments when one wants to stop pedalling momentarily - I had one last week after hitting a large pothole that I hadn't spotted. I now feel much more comfortable on the bike (although hand/arm tiredness is still an issue on hilly 200s, and I'm not yet confident that I could complete a 600 in comfort).
Haven't worked it out accurately, but think I can comfortably do around 150rpm for a while now, and peak at around 180 but can't sustain that. Rode the Gospel Pass 200 on the fixed yesterday, and was pleased to be able to manage the long descents with a combination of manual braking, leg braking and spinning to suit.
I'm also getting much more reconciled to the idea of walking up certain hills/sections.