The campaign on DFX was actually pretty decent for a DF game... which is to say it was pretty bland, but consistently bland. I kept losing all of my save files (classic Novalogic), so I never made it all the way through the game.
The only campaign I've ever really enjoyed in a Novalogic game was the fan based mod for BHD called Deep Jungle (basically, Far Cry assets in BHD, along with the OICW pulled from the game's files). I could not get over the amount of effort put into it.
The AI in BHD was always abysmal - getting stuck on corners, shooting at walls, etc. However, it had incredible music and voice acting.
Also... did you guys read that they found
DFX2 in Osama Bin Laden's hideout?