If Ubisoft would to develop a Siege 2, I would like to see a vast array of attachments and weapon customization, I would get rid of Speed/Armor system and make it so all operators be the same speed and armor type by default (with the exception of shield operators), and make it so that the attachments and equipment you choose for your weapon affects the way you play, like turning a assault rifle into a marksman rifle, or a LMG or maybe selecting some attachments could make you slower but in exchange gives your weapon less recoil.

I think a system like that would fit right in Siege