Thanks for advice guys! Will try Lance. And will try a more STR build. Was under the impression that you just needed a bunch of speed on horseback to get a huge bonus to lance stabs. Guess I was wrong. You do need some decent PS.
Going to try a 21/18.
Your top speed doesn't change much with lots of riding, but your acceleration does. This is more useful if you have more experience at cav, as it allows you to stalk possible ganks or adjust to avoid melee and go from a near standstill to full lance damage almost instantly.
If you just want to plow around holding W the entire time hoping to get random killsteals, high riding doesn't matter so much because you are already going at top speed. Just use a Destrier or above and medium/heavy armor to survive a few arrows.
The most fun cav builds you should hybrid polearm WPF with either 1hand or 2hand. My build for the past year was a higher level 21/18 lancer/2hand cav, and I'd use +3 lance to couch grief and killsteal for the first few minutes of a round, and switch to 2hand once a big clusterfuck happened to stick in the fight with bumps and swings. You could do this with 1hand as well, with added bonus of shield, which is recommended for a new lancer (always RMB if not killing shit). Use 18/18 for a lance/1hand build, 21/18 or 18/21 for pole or 2hand/lance.
Use a heavy lance for fighting other cav and couch abuse, the regular lance is more balanced and I prefer it.. heavy lance has very awkard timing because its so slow, but its impossible to counter a good heavy lance user 1vs1 except with pike/ls or a better timed heavy lance. Lance tears people up but a decent hoplite or 2hand sword will beat you. Light lance is terrible for cav.
Ignore most advice about only attacking people from behind, I don't know what they're talking about. Almost every melee player will try to attack you head on, including shielders. They jump back and try to rightswing unless you are clearly couching a lance at them. They literally jump into your lance and probably double your damage from speed bonus, its hilarious. Hoplites and 2handers I always attack head on with a lance as well, they usually aren't very good. If they are, remember a big trick is to slam the brakes on your horse right before contact. This makes an enemy lancer or infantry completely misjudge their timing and become vulnerable.