Recovery pants have been around for a while, Nike's just now getting into the game I guess.
For the record I LOVE my recovery pants. It's like having a portable use anytime ice bath. I usually wear them either during the day after my tougher workouts or at night. I'll feel more refreshed and recovered the next day.
My guess is that Nike's are going to be just as good as just about any other brand. Maybe some other brands like 110%, CEP, CW-X, etc will make higher grade stuff. Honestly if it says it's a recovery grade and it costs around $140-$200 it's most likely going to be a decent product, CEP however is medical grade and as far as I know has the highest compression grade. In my experience the size fitting scales are pretty accurate too, if you're bouncing in between two sizes go with the smaller one. I have a pair of 2XU's and I love them but they're getting kind of old (2 years) so it may be time for a new pair.
Best of luck.