First of all let's compare loomed weapons so it's a better comparison because most players have their weapons loomed and talking about unloomed stuff would be pointless.
- MW Heavy Lance is 11 speed slower (speed of 75) (compared to MW Lance)
- MW Heavy Lance has 26 pierce damage which usually (when I'm playing as a footman with around 60hp and 59 body armour) deals damage of about 20-60% so I am still fine with like 40% hp. If it's couch it is stranger because it may take from like 40%-100% of hp. You can 1hit only if you hit the head with stab or with couch or when enemy was wounded.
- From the way of holding your H Lance you gain around 2/3 of your 10 length bonus. It seems to be something around 2/3 of the lance in front of the hand and 1/3 of the lance behind so you gain something around 7 length.
- Even though your reach is bigger than Lancer's range, normal lancer can adjust his maximum reach easier because his lance is 11 faster and therefore for lancer it's easier to get maximum reach in needed moment. He controlls max reach better and it lowers the advantage of heavy lancer.
- Normal Lance with 31 pierce is probably most of the time 1hitting (haven't seen many of them, that's only assumption). As a weapon with more damage and higher chance of killing an enemy it is better weapon to backstab. As we all know the best way to be a succesful cav is to backstab a lot so the risk of getting killed is decreased to minimum. As a backstabber you don't need that big length of the weapon because nobody is going to attack you anyway. Length is only good against aware enemies or other cav though lance's speed advantage lowers the heavy lance's advantage.
Cotgs_A.... (I am sorry I can't remember the name) is a good lancer on a destrier using a normal lance. It is really challenging to dismount that player. When doing all this accelerating and braking etc. you can use your speed advantage by minimalising effectiveness of proper timing of a heavy lancer and therefore cav duel is kinda even.
What I want to say is that it's not said that good h lancer has to win against good lancer and that as a cav with a lance you can feel the timing better with a faster weapon and fighting against ground units doesn't have to be harder.
What I don't understand is why they lowered the damage of the heavy lance so much while leaving lance with v good damage. I sometimes use it at +0 because it still has 2 more pierce than my MW heavy lance. Also if I get dismounted I have bigger chances of surviving with lance than heavy lance because of damage and speed so I don't need any sideweapon and I look much cooler ;-). Also lance is nealry two times cheaper than heavy lance.
If all cav changed to lance, it would increase their backstab effectiveness, they would hit harder than before patch, they would pay less upkeep and they wouldn't probably lose effectiveness vs infantry (I tried to explain above), therefore I am afraid if cav went for normal lance, sooner or later it would get nerfed in the similar way making it very similar to current heavy lance, so using a lance would be just a temporary solution.
As a +3 h. lancer (alt) I am going for 24/18 build with 8PS 6Riding and 3points to be placed probably in WM I will be pure cav. These 2 more points placed in power strike will somehow reduce 3 less pierce damage. I will suck dick on foot but my cav effectiveness will be unchanged I hope.
And rly, what da fuq was the latest patch... MW Miaodao with 45 cut 115 length and 97 speed... madness. 2h weapons are uneven now. some got extremely buffed with like 2 damage and speed or even 3 damage like axes etc. and all the items kept their prices... I would suggest that if devs make good items average, they should also do something about the price of those items.
Anyway changing h lance's damage into cut wouldn't be good because you can always kill lightly armoured people with lance+bump combo. Weak foot armour (because the bump damage you receive depends on the leg armour that you have if I am right [heard from somebody]), so weak foot armour will make those lightly clothed people suffer a lot from bumps and changing lance's dmg from pierce to cut wouldn't really change anything. Also it seems a bit logical that a speeding pointy sharp spear should have decent damage against armoured units.
for all TL;DR,
lance is a try-worthy item, devs don't really know much about cav, changing stats without touching price shouldn't take place, length of the weapon isn't that important when you backstab, damage is important when you backstab.
I feel like Joker now...