I actually learned to ride on one as a kid (still get to ride him whenever I make it out to my friend's) & they're great. I also know of 2 breeders within an hour of my place who would agree that they have wonderful
temperments & are very docile.
My friend's gelding (in avatar) was a 4-yr-old stallion when her parents purchased him several
years ago. He wasn't broke to ride & her dad just hopped on him one day & he's never given them any issues since. Within that same year he had his little daughters riding him in the pasture.
The only common problem i've heard of with Fjords (the gelding I speak of has the same issue as well) is they tend to have "hard mouths" & like to lean into the bit. He was never taught to bend either, so it is near impossible to turn him at a run! Such a fat, lovely head lol!
They're also very easy keepers. They were feeding Shiner about 10 pounds of hay a day over the summer (he was in a pen with NO grass) & he's still incredibly over weight!
I'm actually in the process of possibly purchasing one of my own. Just deciding between a gorgeous 2-yr-old gelding or a mare