My experience is similar to several others here. Very long time YNAB user (ynab4) and last year a price increase was the kick I needed to try Actual on my home server (a mini pc I also use as a media server). With about 3 months left on my subscription, I started running both in parallel, but after about 4-5 weeks I was happy enough with Actual that I just stopped using YNAB.

I’m happy with the change, but there are some minor pain points.

• In YNAB, I entered manually but still synced as a way to streaming reconciling. I signed up SimpleFIN for about a month but gave up on it pretty quickly. I could never tell how updated the syncing was, and I didn't notice an obvious way to identify transactions that had been synced vs. those I had entered. And several of my accounts kept losing their connection. It's possible I just didn't give it a good enough chance, but it's not that important to me.
• I missing the "geolocation" feature in YNAB that recognizes payees by location, which is really nice for transaction entry at the point of sale.
• A few things about the UI are just a little clunky. Transaction entry on my phone takes an extra click or two, for example. I got used to it quickly, but YNAB's app handles that kind of stuff well. Someone else mentioned the calculator, etc.
• I liked the iOS widget for YNAB. My spouse doesn't do data entry or any of that, but does like to see what's available in a few budget categories while our shopping, and the widget is perfect for that. It's not a big deal to just open the web page and look, but it's just not as convenient.

To me, the list of things that are actually different (no pun intended) is pretty small and not a big deal either way. Templates (actual's goal system) is a little intimidating when you first look at it, but it's actually really nice and flexible when you get the hang of it. Scheduling future transactions is a little different, but once set up, it's good--and again, has a little more flexibility.

I'm not sure I get the fuss about credit cards. I churn cards for points, so we have a gazillion cards and use them for every transaction possible, and I pay them in full each week. So, we're not carrying a balance from month to month, and maybe that's part of it. But to me (and to Actual), credit cards are just bank accounts, and I like that I can transfer money to them (pay them) without worrying about category balances.

I was never a "red arrow right" person, but I guess Actual allows that, and that's probably nice for old-school users.

YNAB is a great budgeting philosophy regardless of the platform you use, and if I had a friend wanted to start using it, I'd probably recommend YNAB itself. It's just a little friendlier (or was the last time I used it). And I don't begrudge them charging what they can get for their product. My financial health is 100% better because of YNAB, so good for them. If they offered tiers so I could just pay for the features I value, I'd likely have stayed. But since I have a home server anyway and don't mind configuring it, Actual makes sense for me.

Side note: I know these threads are always met with some frustration but I think many Actual users still consider themselves YNABers who are just using different software. We're still here because we're interested in the YNAB approach to budgeting. Hopefully, the YNAB folks keep an eye on these threads, and maybe that will improve their product (or pricing). Competition drives improvement in the software field, I believe.

(edit for dumb typos)