It is really Hard Candy. The album has a very clear direction, the tracks compliment each other v well and the production is top notch, with attention to details and great intro/outros here and there. Its very round, robust. The same can't be said for the others. RH for example had potential but it ended up being like a festival of fillers and unpolished songs that somehow got detached from a main theme/sound if there is one.
MDNA is honestly her weakest album ever, that's too bad.