I was really looking forward to this game from the very start. From Wartime Command to WW2 RTS, and Theatre Of War. I think it's a good game, but it didn't worth the wait in my opinion.
I have to two reasons, first is unit management(for infantry) is clunky. They're too slow to follow your orders, infantry animations drive me crazy, and they do stupid things that you never expect. IMO this game needs something like COH squad management, infantry taking cover behind obstacles automatically, firing properly and having fast and smooth animations for that.
Second is, the game is pointless. The range where fighting starts is vast, and having only a few units at your hand it quickly becomes your Panther driver vs 4 T-34 and lots of infantry after 10 mins of fighting. There is not any mission diversity, all the maps are same, no excitement at all. There is no connection between missions, and you have to be an excellent "coder" to make proper missions for your taste. I wouldn't want to spend 2 weeks to just to get a well scripted mission done to be honest. Then comes the multiplayer, it's horrible. No point in playing at all. It's mostly 4-5 vehicles and a few infantry per player, and no objectives other than playing a team deathmatch.
What I expected was, that us being a Division commander, we would advance through town after town in a big map; defend, attack, circle, try to break out and fight in intense city fights. More like a "Dynamic Campaign" but according to history. For now, I think the only strong side of TOW is excellent vehicle combat modelling.
For the add-on, I don't think it will make a huge difference. Sure it sounds interesting with some fixes and lot of things promised, but they are limited by themselves. They made a wrong approach with a very complex structure for the game, and now they struggle to add even basic things because it conflicts with the other things and make the process unbearable. Take mortars and movable HMG for example, IMO it's not a big thing for a developer but they can't add these even for the add-on.
I may sound pessimistic, but TOW is a very ambitious game in some areas and just because of that it's a half-finished game in my opinion. Add-On probably will make it better, but if they want to be successfull with the series they need to make a total overhaul and refinement of the game.