I was a bigger fan of the Benning performance in AMERICAN BEAUTY, which many people found over-the-top. It was in perfect sync with the satiric tone of that film, and underappreciated because of that level of stylization. But AB was a more commanding vehicle for Benning, and was widely seen. If she wins for Julia, it'll be like Jessica Lange's 2nd one -- for that film NOBODY saw (the title escapes me! I'm sure someone will chime in... Blue something?)
I think the depth of Swank's performance is underappreciated because it's so unadorned, so un-actor-y. She doesn't pitch it for our sympathy, or uploife, or in any way 'comment' on the character as she plays her. There's none of that slumming to play a down and out type. You actually believe she'd take meat home, and live in those borderline slummy digs. And she so resists overplaying the father-daughter bond with Eastwood. What could've been sentimental is clean, simple, emotionally full. She also doesn't 'hide' behind the role, by adopting a "boxer" demeanor. I saw it twice, and was more impressed on a 2nd viewing.
But at least we have good women against good women -- Imelda's simple work is equally affecting.
"I'm a comedian, but in my spare time, things bother me." Garry Shandling