personally, i hope they're not going to show the back split open all gory. the chestbursting scene was magnificient because it was an iconic moment. also, it's gore was somewhat reduced due to the t-shirt covering up the 'gaping hole'.
i don't particularly like that we're going to see the spine break open and see it flee, to be honest. well, if we're actually gonna see that.
i think personally, the implied hurt and damage would do much more as it would force the viewer to use it's imagination and that automatically plays with your senses. If your just gonna see it, it's only going to momentarily affect the eyes, but there is no 'sense' and it won't make such impact to be honest.
it immediately blunts the whole thing away.
If you'd see like you see in the trailer, his back starting to crack, then see his face and fall to the ground and some uncomfortable sounds of bones cracking, painful screams and sounds of hurt, some blood-gushing sounds [ the sound of water squirting is a common used feat ], and seeing the absolute horror and shock on the faces of the people around, to me does a lot more then just bluntly slapping some cgi work full-on where you know it's fake either way, and then the moment passes on like nothing.
the suspense is much more intense then an actual reveal.