It's $20 to remove ads permanently. You can still use it for free with ads. For me I see a small box ad every 20 or so posts. I don't personally find it intrusive. I plan to pay for one of the high polish apps after a few more come out and I find the one I like best. $20 once is completely worth it for the value I get out of it.
I think it may be a bug, but I have not seen a single ad so far. There's not even a spot for ads to appear. I had Sync Pro on Reddit so it has been the exact same experience I had on that
It would be awesome if it did haha, I paid $2 for Sync way back in 2014 and used it nonstop, but I think that I've seen that Sync for Lemmy was going to be, for all intents and purposes, entirely separated from Sync for Refdit
Even if you don't find it intrusive, it is. Ads are incredibly powerful, that's why they pay good money to get them in front of you through any means possible.
A month from now you are going to look around and think to yourself, "damn, why did I buy so much of this sponsored content? I don't need this much sponsored content"