i remember playing this in my childhood but does it run well and smooth on current computers windows 10 ?

It works.

KKnD Xtreme nearly perfect, except if you tools to speedup the game or making it run in window mode - sometimes a little unstable.

KKnD Krossfire has some bugs which appear to me. To be more specific one single bug sometime occurs: "cannot create unit" gets spammed and you are unable to build anything (the cpu cannot build too). So save often and restart the game when this bug pops up.

Also the Multiplayer keeps desyncing for me.

But all in all its defenitly worth buying and playing under windows 10.