I don’t think it’s too much beer & pretzel. Now, I haven’t played Unity of Command, but I have the impression that that game is more in the beer & pretzel vein than PC, although I might of course be wrong. PC is basically an updated version of Panzer General, so if you liked that game, you’ll definitely like this one, too.
Personally, I do think that PC is a bit on the light side, but my go-to WWII is (and has been for a year or so) War in the East, so that doesn’t necessarily mean anything. I still think that PC is a great game, though.
Field of Glory - Poor documentation and doubts about how good the AI is leaves me not sure if this is for me. Otherwise, the scale and subject matter appeals a lot.
If you’re interested in the scale and subject matter, you need to play this! Even though you say that you’re mainly interested in the SP part, you really should try out the MP part as well, since that’s were it gets interesting. MP games are very easy to find and/or setup, using an integrated system, and if you set up a game, chances are that you’ll find an opponent within 15 minutes. I still play the SP part, though, but mostly in between turns in MP games.
Regarding the documentation, yes, it sucks, but there is a helpful wiki, and the rules are relatively simple, so it shouldn’t be too much of an obstacle.
Be aware that there is a bunch of relatively expensive expansion packs, each of which gives you access to more units and historical battles, that you won’t otherwise be able to use/play. It does seem like they’re milking their customers a bit (I personally bought 3 or 4, and I’m still not sure if I think it’s worth it). Even so, they’re apparantly quite expensive to produce, and it’s not certain that they’ll be making more.
Anyway, this game is great! You should get it.
I’ve also seen positive comments about Decisive Campaigns: The Blitzkrieg from Warsaw to Paris, Advanced Tactics Gold and Commander: Europe at War Gold. But it’s hard to find much information / reviews for these titles, and I have little grasp of how playable (size-wise) the scenarios in them are. The lack of demos is discouraging as well.
I only have the first one, and I’ve only played it briefly. I have to say that I found the initial impression a bit off-putting, but since I haven’t given it a fair try, I’ll withhold judgement. But Spelk, who’s a member of these forums, liked it a lot, and did a couple of AAR’s that may help you decide if it’s something you might like.