"Third World War" is one of my favorites from back in the '80s; my brother and I played a lot of that, as well as Victory Games' "NATO". I think one of the reasons I became a big Chadwick fan was TWW.
TWW doesn't have to be a monster game, the four fronts are separate theaters. Arctic Front is the smallest, in terms of frontage, and might be my favorite. It's also possibly the most affected by die-rolls (Norwegian Sea control). Persian Gulf has a diplomatic pre-game card game, each player trying to win allies before the shooting starts, it can be interesting. That game, and Southern Front, both feature a lot of open space that armies might not be large enough to control completely. TWW: the Battle for Germany is the main event, and can turn into a slugfest or a rout, depending on how well the Soviets can make their attacks.
Overall, I'd say there is a noticeable, but not overwhelming, advantage to NATO, especially in the long-term. The Soviets have to drive hard to win.