I don't really agree that these two albums have the same kinda vibe though...
Even though Beyonce continues to grow as an artist and keeps getting better and better, Rihanna stays at the same level but since 'LOUD', she has started to decrease in quality and is seriously going to hit rock-bottom shortly especially after the release of the catastrophic "Unapologetic" ...Just what was she thinking with that album! The only good song is "Diamonds" ... possibly "Stay" !!!
Despite all of this, 'Rated R' is not only the better album between the two, but also Rihanna's best album ever! I mean with tracks like "Russian Roulette", "Fire Bomb" and "Cold Case Love", you can't fault it! Although, I'm not a huge fan of "Photographs" (maybe because it has Will.i.am on it!!!!)
I feel like "Run The World (Girls)" ruins '4'. But to conclude 'Rated R' is better than '4'.