So DC, like Marvel, have three levels of binding quality. First is the standard hardcover bindings. These are for the books that have the same page size as a trade paperback, just in hardcover format. These have glued bindings, just as Marvel's do.
Next is the oversized hardcover (Marvel doesn't have a name for them which makes it a little more annoying to point out, but DC calls them Deluxe Editions). Marvel's and DC's for a long time had glued bindings. For the last few years, Marvel has used a cheaper sewn binding for it, but still superior to glued. DC for the last year or so moved mostly to a glued/sewn method (Swamp Thing Deluxe, Multiversity, Batman 100, etc). It stays open better than a purely glued book, but it's still susceptible to gutter loss. However, the last couple of deluxe editions DC has put out have had sewn bindings that are actually better than the bindings Marvel uses in their OHCs. These books are Green Arrow by Jeff Lemire and DMZ Vol. 5.
Here is a comparison between a modern Marvel OHC (Hawkeye Vol. 1)
and the Green Arrow by Lemire Deluxe
to show my point:
Last we have the omnibus. Marvel long ago used glued bindings but for a long time now they have used high quality sewn bindings. They're at the top with bindings, IMO. DC has been very inconsistent with omnibus bindings, though they've improved a lot in the last couple of years, and their bindings of late are fairly close to Marvel-quality. It should also be stated that DC also has an Absolute line of books, and those bindings are always high-quality.
So there you go; more information than you ever needed or wanted.