I'm a fence sitter when it comes to the whole thing. I see little requirement for them beyond corporate greed. These weren't made for comic fans, they were made for the book store, to have additional material available to the now millions who have purchased the original and don't know anything of its context or importance or, even, it's standalone nature. On the other hand, they have some creative talent involved that has to raise eyebrows. Adam Hughes, Darwyn Cooke, Azzarello, Steve Rude, Jae Lee, JG Jones among others. They certainly didn't shy away from approaching top notch creators (I can only imagine who said no, if these were the people who said yes). There's also the curiosity factor. I love Watchmen, and appreciate it more every time I read it, and no manner of extensions or additions are going to damage that greatness for me, even after all this time. The same with Star Wars, the questionable prequels (though I do like some aspects of them), can't damage my dozens of viewings of the original trilogy or the near perfection of Empire (now if Alan Moore and Dave Gibbons went back and "special editioned" Watchmen, shoehorning in new scenes from Before Watchmen, then it might start tainting that original experience).
My stance has been, pretty much from the outset, that I want to read them out of curiosity but I don't really want to pay for them. Basically, I've been trade waiting for them (and then waiting for them to pop up at my library). With Comixology's 99cent sale on Watchmen and the first issues of Before Watchmen, I thought it was cheap enough to at least sample a few of the books I was curious about.
Dr. Manhattan probably piqued my interest the most, because I don't even remember the last time I saw Adam Hughes do interior artwork. The long promised All-Star Wonder Woman he was supposedly doing never materialized (what a bust the "All-Star" concept ultimately turned out to be) so eyebrows were raised when he was counted among the Before Watchmen team. Well, I can say his artwork looks great, and is worth the price of admission. The story from J Michael Straczynski is readable but as suspected it doesn't feel like Watchmen. It effectively plays with timelines, integrating events Moore constructed with new threads and trying to weave in new background elements that theoretically influence the character, but it feels inauthentic. It takes until the last page before it gets to the crux of the story, what precedes it is at times laborious set-up. It's not a bad read altogether, and given that final page, I would like to see where it goes (and see more Hughes art), but I'm not exceptionally excited about it all. Frankly, I realized this isn't a character (nor were any of the Watchmen) I was wanting to read more about.