What I love about the Win- games, apart from what others mentions here, is that the "benevolent dictatorship" of the devs Don and Andy ensure the games difference between MBT and WW2 is minimal, and that any changes are thoroughly tested and verified. And they listen to the community
I came here from having played WaW a lot - started playing WinSPMBT to get some modern action, and found having to switch between them for PBEM games was tedious since keys were different and so on. So I persuaded my PBEM mates to change to WinSPWW2 as well
I've tried SPWAW again last year, but like many found the pace too fast and the graphics too "shiny and colourful" if thats a correct term
And the multitude of mods there was for WaW a while caused much confusion when installing... I see they now have something called SPWAW Enhanced but never tried it.