They definitely did a good thing with the way they handled prestige. Before there really wasn't any point to it other than getting a challenge. Now you actually don't feel that penalized. You still have to unlock the individual weapons and perks (unless you use a prestige token to unlock permanently), but the weapon accessories remain. i.e. you have to unlock the weapon again but you can immediately start using the accessories you already had unlocked (unless you choose to prestige the weapon itself, which you can).
I would recommend getting it. I thought after MW3 I had lost interest in the series, but I have a new found love. Another tidbit: when you prestige, you get a permanent unlock token so you can permanently unlock a weapon for use even after prestiging.
I've played enough now that I'm used to the maps, and I can say that they are very well designed. Something here for everybody whatever type of gameplay you prefer.