Germany definitely has a bit of an edge, but when played right (i.e. using the air power correctly) it’s not impossible for the Allies to win, or at least be competitive. My dad and I have been playing this one again fairly regularly, and we’ve had several extremely close games (coming down to the last two turns, and often seeing where specific tactical mistakes tipped things in favor of the Axis rather than dice rolls/inherent imbalance). We just recently played one that came down to two German tanks clinging on to St. Lo, thanks to me (Allies) panicking over Caen and diverting a few too many American tanks, for example. The Allies have less margin for error, but it’s by no means insurmountable.
When I first got this game when I was younger I initially thought it was heavily unfair, but I had missed the 8 unit per side stacking limit in the rulebook. Once that was implemented, the games got a good bit closer and more interesting. Though Battle of the Bulge is still my favorite theater game, I still enjoy this one a lot. I also find it’s a good one to get newbies introduced to the A&A combat system. Since the reinforcements are predetermined, and the turns are kept track via cards (plus the very doable 2-3 hour playtime), new players (or those unfamiliar with even light wargames) don’t get quite so overwhelmed by all the choices a regular A&A game presents. Because of this, aside from my Revised and 1942 editions, D-Day is probably the one that’s gotten the most use on the table, though oh do I wish I could find more people willing to play Bulge.