I see that HPS Simulations is releasing a Campaign Gettysburg as the next installment in their "Campaign" wargame series. I'm still playing through their Campaign Franklin, so I'm not going to rush to order Campaign Gettysburg, but it sounds like an ambitious, sprawling attempt, if it's including Brady Station in the campaign. Hopefully it'll have more branching choices than Campaign Ozark or Campaign Franklin seem to have. I rather think it defeats the purpose of a "Campaign" game, if the scenario sequence is essentially linear.
Campaign Ozark, while fun and interesting on a battle-by-battle level, didn't make a particularly good campaign set, if only because it was designed as three mini-campaigns - summer 1861, early 1862, and fall 1862 - which don't flow into each other. Since the AI in these games tends to be fairly weak, Campaign Ozark campaigns tend to end up as a brief, single-battle routs. I had to play the stand-alone scenario to even get to Pea Ridge as the Union in the early 1862 campaign - played in campaign mode, it was too easy to destroy the Missouri Rebels in a piecemeal battle before you even got across the Arkansas border.
Campaign Franklin is more unitary - it's just the single central Tennessee campaign - but still very linear. Battle at Spring Hill; battle at Franklin; battle in front of Nashville. Franklin is somewhat challenging as the Rebels - interesting, at least.
Campaign Corinth has been the best installment up to this point. It was large, heavily branching, unitary, and sprawling. There was a lot of variation, and you could go all sorts of interesting places. The structure of Union reinforcements and the branching meant that the typical annihilation-style combat didn't curtail the campaigns prematurely, at least while playing as the Rebels.
I'm a little disappointed that they went with a Campaign Gettysburg. Tiller's old Battleground Gettysburg is still playable, if somewhat elderly and creaky. Gettysburg is such a massive singular battle that I can't help but think that it isn't really suited to the "Campaign" conceit. Additionally, there are a ton of neglected campaigns and battles in the East that could have been interesting. The Overland Campaign of 1864, for instance, would be well-suited to a "campaign" wargame style, if rather oversize for the engine. Of course, a Campaign Gettysburg is, itself, rather oversize for the engine. A Chancellorsville installment would have made for an interesting maneuver wargame. You could follow the old "Battleground" conceit, and recycle the Rappahannock battlemaps for a Fredericksburg-Chancellorsville-Wilderness packaged wargame. A Penninsular/Seven Days wargame in the "Campaign" mode would be massive but interesting. Hell, even a packaged Valley set along Campaign Ozark lines would be fruitful - a "Jackson in the Valley" campaign, combined with an "Early/Sheridan in the Valley" campaign sort of thing. It would even suit the scaling limits of the "Campaign" engine. But Gettysburg? It's been done. Again and again.