Walker is just ham-handed and repetitive. I remember what it's like in a general sense but barely any of the individual parts, although that's kind of how it felt while I was watching it too.
I mostly agree with Ebert.
Maybe I'd quibble about,
Although the ads for "Walker" don't even hint it, this movie is apparently intended as a comedy or a satire. I write "apparently" because, if it is a comedy, it has no laughs, and if a satire, no target.
I strongly agree that it has no laughs/effective humor, but the target is obviously America's foreign policy. But it's just a big circle jerk. I have a hard time seeing why anybody would get anything out of its "satire" aside from the satisfaction of seeing something that conforms to their own attitudes.