Have you ever tapped W after you thrust?
Yes, I do it all the time. Although I have doubts if it hurts or helps. Yes you are adding "speed" on one hand, on the other you may close distance and thus reduce damage much more due to "effective" range mechanics. And it's much more difficult to determine optimal attack distance for trusts then it is with swings because of 2D nature of the computer graphics.
I ques I do it instinctively now after playing with spears in Viking Conquest, which had better spear combat mechanics.
I very often 1 hit enemy's while staying out of range using 160ish length spears.
That might be the case when you attack enemies that does not face you. But you can do the same and better with any other weapon in such a case. Movement adds the same damage bonus to spears as to any other weapon, other weapons however have higher base stats.
depending on armor type I average 2 hits per kill, however the important part is staying out of range and having enough attack speed to force an enemy back each time they enter the kill zone. If you never need to block your DPS increases dramatically, that is the strength of spears in the game you can constantly attack without ever needing to block.
You will stagger enemy only if you hit him. If he has a shield or blocks you with the weapon, he will not get staggered and will close distance. And you are back to the "ineffective range" problem. I was already arguing before that trusts should not have such a penalty for non optimal distance, as trusts does not rely on momentum as much as swings do. That alone would probably improve performance of spears a lot. I also suspect that that was how spears were made effective in Viking Conquest.
Again there are very few spears you can buy, that are good - the imperial mendo is really they only "good one". Most spears in the game are designed around cavalry which is require you to have much more length than desired in a dueling situation.
I am not in to smiting much, I don't like this feature in principle. But from a limited experience plying with it (I do use it to level my companions that have some starting skills in it) it seems that while you can potentially craft some powerful spears, you can craft even more powerful other weapons. So balance wise, spears still loose.
I was fiddling with shorter spears as I really like idea of a spear combat on foot, and while shorter spears are definitely way to go in foot on foot combat, they still under-perform in the damage department. I will check imperial mendo however, because I did not try it so far.
It's not that spears are not viable weapons in the game, there is clear improvement form Warband, it's that you can be more effective with other weapons with less effort. Moreover other weapons are also more forgiving to mistakes. When you make mistake with the spear, it's much more difficult to escape punishment.