Good lord this cast is fantastic.
Clooney is great, but it's really about the supporting players. Wilkinson and Tilda Swinton are absolutely amazing. Pollock was great as well.
The scene between Clooney and Wilkinson in the jail lock up stands out. The final scene between Clooney and Swinton might be one of the best in film. Just spectacular work from the cast.
Why isn't Tony Gilroy getting more jobs at director?
His stock took a really big hit after "Duplicity." And the "Bourne Legacy" really underperformed at the box office. There's also been some friction between him and Matt Damon that has maybe resulted in him being "difficult" to work with. He's regarded as a great writer but I think producers are at this point hesitant to allow him to direct anything with a significant budget.
RE: the acting / casting... I totally agree. In addition to Clooney, Swinton, Pollack and Wilkinson there are terrific smaller performances by Dennis O'Hare, Julie White (who has a single, virtually inaudible line), Michael O'Keefe, Bill Raymond and Merritt Weaver. Plus a voice-only performance from Tom McCarthy (lawyer who talks to Michael about the hit-and-run) and a blink-or-you'll-miss-it turn from Broadway great John Douglas Thompson as a police officer/jail guard.