Get a faster horse, or get more power strike. With 8 power strike on a courser it destroys people, even with 6 PS on my level 30 alt it's a beast. The reason I use it is because it allows you to go up against any other lancer out there and not be at a reach disadvantage. I also like that you can outreach a couched great lance if you time it just right, you can't do that with a lance.
The lance is an amazing weapon too though, I think it's the best lance overall (can still take on other cav, but likely will get outreached by a heavy lance user that is competent). It is fast and hurts like hell so it's great for playing cav the correct way, which is attacking infantry (not other cav). But since I have A.D.D. and attack other cav I use the heavy.
Also san makes a good point about the hold times, it's very important to be "refreshing" so you're not holding for an extremely long time.
I think you're just bad at cav, and by bad at cav, I mean only a 3:1 k:D, not 4 or 5 to 1.
KDR is not really a good indicator, at least IMO. I think I'm one of the best cavalry players in NA (at least whenever I'm playing, even on my shitty work laptop nowadays). And I only have a 2.3:1 KDR.
10406/4449, 2.3:1
You're basing your numbers off of people who would leave the server if they lost one round to avoid having a bad KDR. They only cared about their KDR, not playing seriously. Cav like me, who continue playing even on non-cav based maps are going to have that hurt their potential KDR. But since I don't care about my KDR, I'm not going to leave to just artificially pad it. I can easily go 5 or 10:1 KDR on cav friendly maps.