Honestly I would prefer to be able to buy a separate "Pro" version from the Play Store, without an in-app purchase. There have been issues in the past where in-app purchases didn't get recognized or when ads suddenly started appearing for people who bought the ad removal option.
That doesn't mean it won't ever happen again. I just have less trust in an IAP model. It's inherently more fragile because it does a license status check with Google every time you launch it, whereas a one time purchased app doesn't need to ask permission.