Rouncey
hit points: 95
body armor: 16
difficulty: 3
speed: 41
maneuver: 41
charge: 20
Price: 9,010
Palfrey
hit points: 85
body armor: 12
difficulty: 3
speed: 42
maneuver: 41
charge: 18
Price: 13,214
For exactly 1 more speed you get a horse that is 4000 more gold, 10 less hp, 4 less armor, and 2 less charge. I never see palfreys being used and it is obvious why.
Even if you can argue that the 1 point difference in speed is balanced by the reductions in the other stats, can you argue that the pricing makes sense? I suggest at the very least to cut the price of the palfrey in half or make it equal to the rouncey's. Playing cavalry can be expensive, so I would assume players will gladly take 1 less speed for less upkeep (along with the additional stat benefits). Just stare at the progression of the horse equipment page for a bit and you'll understand the absurdity. I don't think one can argue that the palfrey is a manouver role horse either (in the progression): the sudden drop in difficulty doesn't make sense for that and 41 manouver is standard for non-HA mounts.
*edit: Another suggestion might be to nerf the rouncey, or increase its price instead.