What I mean by that is Spears's presence on the songs themselves seems like almost an afterthought. Her voice has never been among the elite in the industry, and has become less of the focal point of her albums with each passing release, but on "Femme Fatale" it almost seems like the goal was to minimize Britney's contribution as much as possible to let the producers shine instead.
Now, if you're a fan of dance/club music, then that may be a good thing. The beats are thoroughly well-produced and strong throughout. However, they feel entirely homogenous. Rather than there being a tonal ebb and flow to the album, there's just a never-ending pulse, as if the goal of the music was to get the listener to maintain a 200 bpm heartrate for the entire listening experience.
It's possible that in this post-Rebecca Black world, my tolerance for meaningless, overly-robotized vocals has been lessened, but it's also possible that Britney is something of a guest star on her own album. Which gets me back to my initial question: If you made this same exact album, with the same exact production and vocal quality, but instead of Britney Spears it was from an unknown artist (let's call her "Becky White"), would it be successful? Which song would be the breakaway hit? Sure, "Hold it Against Me" performed well on iTunes, but again I feel like that success is more due to the Britney Spears "brand" than the music itself. And in the end the album feels like a collection of talented producers using the Britney brand to promote their own works, at the expense of Spears's music herself.
There are a couple of songs that I can see myself listening to repeatedly, led by "Criminal", which is probably the least dance-y song on the album. The Max Martin/Shellback production duo (the same pair responsible for "If U Seek Amy" and "3") seemed to work WITH Britney's vocals on this one, rather than over them. "Seal it with a Kiss" has lyrics that may as well have been written by a 4th grader, but damn it if it isn't catchy as all hell. On the flip side, there's "Big Fat Bass", the Will I Am collaboration which may be the seventh sign of the Apocalypse.
Overall, my opinion of the album "Femme Fatale" probably leans toward the positive. However, the verdict is still out on Britney Spears's "Femme Fatale" -- if there even is such a thing.