I like the song (in relative terms) - one of the melody lines really sticks in my head. I agree it sounds like Rihanna, but that's not the worst thing in the world. I'd never argue that as a record it was fresh-sounding, but there are many, many worse records under the electro-house banner imo. Have you been to a gym recently?
Surely not. Surely Guetta is the blandest, most homogenous example of the EDM trend. Everything in Titanium is sound-a-like; Sia sounds like Riahanna, the kick sidechained like a motherfucker, the lead sounding like every electro-house record made in the last decade. To me, there is nothing even remotely fresh about the sound of this record.