When I'm leveling and have 3 riding I do a lot better than trying to fight on foot. I honestly don't mind 3 riding on a rouncey, just have to play smart (as I suggested earlier). You shouldn't be riding off in the distance far away from your infantry. You should be staying close enough that you can retreat to your infantry if a cavalry on a courser tries to chase you down. You do that, and 3 riding will be just fine to use.
This is true.
3 Riding can be fun, and you can do pretty good with it. The key is to play smart, and be cautious. Once you get on that horse, realize your speed, and become hypnotized by the thundering hooves....it is easy to get carried away and start zooming around the battlefield with bloodlust trying to trample everybody down. Then you die.
DO:
think ahead and play it safe
Flank enemy positions
support friendly infantry by bumping engaged enemies
DONT:
engage enemy cavalry
get shot by archers
charge enemies who are aware of you
get cocky cuz you're on a horse
Doing the above things can help you have fun and perhaps a bit of success with 3 riding! I recommend getting some armor LOL. When you are on horseback, the "speed bonus" applies to you as well. If you are at high speed and get hit, you will be 1-shot.
Palfrey's are like Rounceys, but worse in pretty much every way.