There are a few drawbacks to the collage feature on Instagram. The first is that there is not a border between each photo. I know that is a visual preference for some. The other drawback is that you cannot add text on top of the photo like you can in apps like A Beautiful Mess.
Despite the drawbacks, the ease of use and efficiency in the new collage creator within Instagram makes it a win in my book! Have you used this new feature yet? Let me know what you think! Also, if you haven't checked out Greg's post about the new Instagram scheduler, be sure to check it out!