I've had to think about it for a few days, but I'm more with Ite on this.
The gunslingers are supposed to be BAMFs, and -- even if King didn't always deliver on this -- he built up a great atmosphere of epic conflict. Heck, the final line of the first book was "The gunslinger waited for the time of the drawing and dreamed his long dreams of the Dark Tower, to which he would some day come at dusk and approach, winding his horn, to do some unimaginable final battle."
Given that this film is supposed to be as much a sequel to the books as an adaptation, I have no problem with this long-awaited promise finally being fulfilled.