It will no longer be as much about picking Stories in one or the other once Instagram comes up with lenses. It will be all about what each network offers on top of whats the new normal (ie. Stories). Snapchat has the potential of doing a lot of mainstream AR. Instagram has its original culture and feed. If Snapchat keep shipping and innovating as fast as it has been so far, it will win long term. Instagram is on defense here. Snapchat is on the offense. On the flip side, Instagram owns distribution, user targeting, and UI/UX familiarity among older demographics. So, converting the older demo into users rapidly will be a uphill battle for Snapchat at least in the short term. Oldies on Instagram can now have a core feature of Snapchat within what they use.