There are very, very minor complaints: the art, while mostly gorgeous, made some character looks like bobble heads at some points. Furthermore there were a couple of pages of what felt like strained exposition at one point. Given how perfect the rest of this storyline is, fitting into what little I know about the DC aspects, and fitting in perfectly with the Star Trek aspects, though, I almost didn't even knock off half a star. These issues bugged me enough to do that, but I have nothing but praise for this storyline.
The references - the ones that aren't made clear from the cover, with the Legion of Super Heroes and original Trek cast - are clever, fit in with the respective canons, and don't feel shoehorned to make this story work. No, the story was created around aspects of these two universes that seemed bound to converge, especially after this practically flawless story!
I can't give away much at all without spoiling anything. So I'll say I found everyone - all the ones I knew - delightfully in character, and I thought all the nods to the Star Trek universe simply charming. I wouldn't have bought this if it hadn't been provided in the Humble Bundle, but, boy, am I glad it was!