while they both use .map format.. q4 player is taller than q3 player. q4 doesn't use lightmapping so level lighting and brush splitting becomes more important. q4 also uses vis portals better so they have to be setup well. Going further q4 uses more guis vs direct push buttons from q3.
Finally wfa 3.5 maps were made when wfa code was already pretty old. We are starting over from PURE scratch. I started with a clean q4 sdk and began making WFR from that.
A little less griping about comparisons this early would be greatly appreciated.