Well, I unfortunately only have one Napoleonics game, and I've only played it twice. I'm looking for something a bit easier to get into, and since GMT is taking its sweet time getting C&C: Napoleonics out, this looks like something to get.
Horus Heresy does have some very neat looking mechanics. I'll admit I'm somewhat neutral on combat being card based (I love my dice), but I'm actually intrigued by what I've read so far.
As for Gears of War, I'll probably give it a pass unless enough people tell me that the mechanics are great. I tend to skip games that are based around a theme or IP I don't have much interest. Though I am watching FFGs new Battles of Westros with interest, despite not being able to get through the first book of A Song of Ice and Fire.