Both are great, and I think complement eachother nicely. Qobuz mostly focuses on label offered music catalogues, while Bandcamp has always catered to indies. If an artist offers their music through Bandcamp, I still prefer to make my purchases there, but if the artist is signed to a label then it's a good shot Qobuz has it.

Either service offers the music in the highest quality provided, though lossless versions through Qobuz do tend to be priced a few dollars higher than the regular album.