As a standalone Bond movie, Quantum of Solace lacks a lot of stuff including Bond gadgets (and Q), Bond stunts, and a good Bond villain.
However, I believe QoS is still a very good installment of James Bond when viewed as the middle chapter of a story arc that started in Casino Royale. This time, Bond Girl Camille actually serves an important plot point rather than being just a simple sex object. Through her, Bond finally gets over his feelings for Vesper and has finally taken on the full mantel of James Bond. Putting the signature gun barrel at the end was very fitting.
The villain this time, Dominic Greene, is yet another "small fry" villain like Le Chiffre in CR. I can only hope that both Le Chiffre and Dominic Green are merely the Quantum's lower echelon of villain-bosses and as Bond uncovers more of Quantum's core operations, we get to meet better Bond adversaries.