I love it.
First, Ben Affleck looks fantastic in the suit.
Second, despite its familiarity as a design, this is a very unique design that doesn't rely on "superhero convention" as many other superhero films are doing lately. It's not all padding and buckles and random layered fabric and whatnot. It's a functional superhero costume designed to evoke an iconic image.
This is the Batsuit I've wanted to see for like...forever.
It's pretty clearly either black and gray or a shade of black on black that makes it look like black and gray. That alone is fairly exciting.
Designwise, what's interesting about this suit is that it has so much going on at once, but it doesn't look cluttered for all of it. It almost serves as a commentary on the character. For instance:
-The "muscle" striations/design and texture and lack of obvious armored plating make him look more organic than any version that's come before. I don't think it's possible for a black and gray design to look much more "beastlike" and intimidating.
-At the same time, the suit has a homemade, lived-in feel, with damages and "repairs" along various lines of its fabrics. Even the Bat symbol itself is "scarred" and appears to perhaps be torn in places. This suggests that the suit itself is made of a durable fabric, not body armor plates.
The torso is just fantastic. The muscles look great, without being too molded into the suit itself. With the emblem apparently being a similar color to the rest of the torso "armor", which is gray, he kind of looks carved from stone, like a living gargoyle or something, and that's just a great effect.
The cowl looks very good, and I think complaints about the roundness of it will go away once he's not so profile, and I'm betting the ears will look sharper and more defined from the front. The ears being shorter makes sense, since Affleck is like 6'4" already. He's pretty clearly going to be able to turn his head. Looking at the features of the cowl, they seem a little smooth and "broad" in places. I wouldn't be surprised if they're going to do some CGI work on it to make it more emotive, but if they don't, it still looks fantastic.
The gauntlets are much sturdier than previous versions have been, but they're not overly complicated a design, either, which I like. If you look closely, you can see "battle wear" on the fins themselves.
The Utility Belt is FINALLY the black pouch belt I've long wanted to see adopted. I hate the fact that he wears a gold/yellow belt just BECAUSE in the comics. It may be tradition, but it makes no sense from a tactical perspective. Finally someone with a brain designs the thing, and it looks fantastic, and creates a worthy visual stand in for the trunks.
They nailed Superman's boots, so I'm not too worried about Batman's looking right.
Last but definitely not least...the cape is a thing of beauty. It's connected to the cowl, it's got the ribs inside it, it's thick on the shoulders, and looks like it will drape incredibly well. And it has the leathery look that really worked for Burton's Batman.
It really couldn't be much better. I look at this as a "modern" Batman design, not just "Jim Lee" or "Frank Miller", though there are nods to definitive elements of both their takes on the character. But to me, this just looks like many versions of Batman we've seen since about 2000 in mainstream comics, with a nod to the New 52 and more recent "lines" of the suit that doesn't overpower the overall design or its classic nature.
I love it.