Visuals
None of these problems are present in Hibike. Most of the time, the CG blends so well, it's almost hard to distinguish.
Nodame: 6/10
Hibike: 9/10
(And yes I'm aware we're comparing 2007 and 2015 graphics here)
Plot/Story
Nodame Cantabile is fun. It's a lighthearted view of how its characters face their fears in order to get more out of their musical talents.
On the other hand, Hibike takes a more serious tone. It shows a realistic situation where an amateur band struggles to get in the national competition while reconciling their conflicts along the way.
Nodame: 7/10
Hibike: 7/10
Characters and Ships
Looking at the main characters, Nodame Cantabile has much more variety in character personalities and design. Hibike limits itself to realistic personalities; characters are hard to distinguish sometimes.
Hibike has a heavily implied lesbian ship. I'm not actually surprised given that majority of the characters are female.
Nodame has it's 'woooo yaoi' moments but the canon ship is still heteronormative. Interestingly Nodame has an openly gay character: Masumi.
Nodame: 8/10
Hibike: 7/10