Let me explain, I am a big fan of Warren Ellis. I have many of his works, and his work does vary, some are outstanding and reinforce my liking of his writing, others are not up to the standard I expect, and others are cliché ridden and just fun. Red definitely fits into that category. It's nothing new, nor is it anything particularly mediocre. It's an enjoyable fun ride, and it's made out to be. Ellis takes the typicality of an action comic book and infuses his own style into the proceedings. Sure you've seen it before, but it's Warren Ellis we're talking about here, and he does retain his own style in this work.
This review is just a precaution to those of you expecting something miraculous from this work. You've seen the storyline before, but with some really well placed action scenes, it makes for a rather cinematic work, which was obviously the point in the first place. And it achieves that quite well! The artwork is well drawn, especially of the main character, who is thankfully, not drawn out in the conventional way. The characters are quite well defined, my favourite being the head of the FBI, always putting himself above the President's, who is unfortunately, not the brightest cherry in the bowl when it comes to decision making.
As usual, Ellis takes no prisoners with the ending and not everything is resolved (which may or may not satisfy you, depending). So on one level it is classic Ellis, but it's also an easy work for Ellis, something he could do in his sleep. If you want his best comics, I'd advise you to look at his earlier work.
So grab the popcorn for a fun ride, just don't go in expecting anything profound, especially from Ellis, who is capable of far, far more.