I think I'm gonna a hold out a little and see how the beta unfolds. I had purchased the no-ads IAP in Sync for Reddit and it kinda always was worse/more fiddely than the (I think equally expensive) Pro version. Purchase didn't always restore after updates, sometimes something changed on the API and the no-ads purchase didn't work for days... Stuff like that, and when LJ came out with Ultra and offered a free year for Patreon backers, it was also only for users of the Pro version...
So please do excuse me for being a bit wary over a no-ads IAP, especially for 15 bucks. This time I would skip that and immediately go for a pro version, should there be one.