I just hate when you can't get the other preorder stuff ever, or when it varies in quality from retailer to retailer. For instance - I recently preordered LA Noire from Amazon, giving me a special suit in-game that gives me a boost to fighting. I don't really care much about that. But ordering from Game (and another retailer) will give you an extra case to solve. What the fuck, guys? Just because I use Amazon as a hub, I get a suit that I really don't care about, while people who happen to prefer Game get a whole new section of gameplay.
And last year, with Napoleon : Total War, there were special units you got from retailer to retailer. And they never released them as DLC. It's just irritating to not get the units you want, even if you're willing to buy 'em, simply because the retailers want to buy customers by withholding content.
To reference another Total War game - this year's Shogun 2. It had an entire faction if you bought the limited Edition. This Limited Edition cost the same most places, but Steam did not have it, on account of normal business disputes. Countries where people can't use Game or Amazon were rather nicely screwed over, missing out on a pretty damn big chunk of content.
Really, I loathe this practice. It's mean, arbitrary, discriminatory and fucking irritating. Withholding existing content at all, be it through "editions", Day One DLC or pre-order bonuses is at best a dick move, and at its worst, it's a despicable business practice that is essentially saying, "Sure, we have this stuff made already, but we're charging you more for it, or we're gonna make you choose between the existing content and lock out the rest, simply because we can."
Fuck that.