The Sculptor plays with some big themes: 
 - the subjective "worth" of art apart from its marketability or external validation 
 - anxiety about mortality and leaving a mark on the world 
 - the importance of artists' work/life balance (rather than a fast-paced single-minded focus on art) 
 One of my favorite scenes was an ode to friendship and shared experience, near the beginning: the protagonist, David, translates memorable moments in his life into whimsical abstract sculptures, and shows them to his closest friend. The friend knows him well enough to be able to connect each piece to its corresponding moment. 
 But I felt the book had its flaws, too. 
 - David is a really aggravating character, which bugs me more than it should because I get the feeling the author wants me to identify with him! He's immature, overly melodramatic, proud, and needlessly stubborn over tiny trivialities (his "promises"). There were lots of times I just wanted to shake him! 
 - The love story felt a bit flat to me - their interpersonal drama didn't feel "earned" to me, if that makes any sense. David tells a girl "I love you" after having just met her... 
 - The ending... (view spoiler)[was a bit sudden, and reminded me unpleasantly of the ending of the 1985 film Brazil (spoiler again if you haven't seen it): the happy ending was all a dream! (hide spoiler)]