From your link:
From vanilla to warband.
Bandits Camp
-> After the first few levels, I basically ignore these. I wont be missing them.
Updated textures and graphics.
New character movement and swordplay animations.
-> Ouch
New character horseback swordplay mechanics--added the ability to change the side of a held slash.
-> Actually I hate that, I have hard time hiting people with swords on a horse now, the sword moves nonstop :p
New character fighting mechanics and animations--added the ability to kick.
-> Nice but I rarely use it. Most of the time I get a free slash on my chest from trying it.
Added a new couched lance mechanic, most importantly being time-limited couches.
-> In vanilla it was super easy to couch, now it is hard. But I think it is for the best, as a balancing measure.
Added automatic shield blocking of some missles even when shield is not explicitly held up.
-> This means in vanilla arrows can ignore my shield if not actively using it? I love how sometimes arrows hit it when on my side, or even on my back. In fact I sometimes wear two shields, so I have one in the back all times. In vanilla this doesnt work?
Added chambered parrying--attacking at the right time in the right direction will parry an incoming attack and deliver an attack.
-> Never noticed it.
Horses now have a linear physical presence that makes it impossible to turn on the spot if objects are in the way. To compensate, horsemen AI is greatly improved.
-> I noticed it, and I like it, for realism.
Balanced parties (the bigger your party, the bigger the parties of roaming bandits become).
Command and found your own kingdom, recruit lords from companions and other factions, and take over Calradia.
Prisoner ransom is now differentiated. Skilled prisoner will price more, while brigands and recruits price less.(Gallary slave marchant will buy them for same price of 50 denars regardless of rank)
-> All this is overruled by the mod so it wont matter.
Buy Land for a productive enterprise: talk to a guildmaster to set up a business that produces goods from raw materials, eg. a bakery to make bread from grain.
-> I liked it, but its kinda broken. Easy money, for me at least.
Multiplayer
-> I dont use it.
Marriage
-> I wont miss this.
Sarranid Sultanate
-> The mod adds even more so...
Your own kingdom
-> Also added by the mod.