In my five years of playing my acoustic/electric Ovation Applause, I've always used Elixir Strings Phosphor Bronze Acoustic Guitar Strings w/NANOWEB Coating, simply because it was the first set I started with and I liked them. Well, I decided to give D'Addario a shot a couple months ago, since they're cheaper, and I seriously regret it. I'm not some guitar aficionado, so yeah, their tone and all the other fancy sound stuff is fine - they sounded a bit more hollow to me than my Elixir strings did, but not a huge turn-off.
The thing I really don't like is the roughness. Maybe I'm just spoiled with the Elixir strings, but every time a finger slides just a wee bit on these D'Addario string, I cringe. Some people may like that sound (a friend who doesn't play said she really enjoys the exaggerated sliding sounds), but for me, the kicker is how it feels on my fingers. I just don't like it.
For all my complaining, I'm not going to give these strings a one-star review though, because I think my problem with them is more personal preference then some actual quality issue.