I have always thought I was a good descender; at risk of being ridiculed as a Strava[insert derogatory epithet here], the 3 KOMs I have are all from descending. However, I've found when I'm riding on an audax, I'm usually one of the faster people uphill, and that there are people MUCH faster than me downhill.
Re. climbs, I didn't have any problems with the hills on the 3.5AA Delightful Dales, but the triathlete I was riding with took what seemed like terrifying risks on some of the descents, and left me for dead, whereas he had to walk the steepest sections.
For me, if there's not a clear view beyond the apex of a bend, I don't dare anything that might mean I have to cross the centre line. Other people seem not to imagine what might be coming round the bend as vividly as I do. I'll take tasting blood over the worry that twisty descents give.