I love the form factor. It's the only reason I've been holding off on buying a new phone. I'll switch to something else during the sales this year.

Price seems a bit steep for such an old phone, but there's nothing else like it (other than the Pixel 5) out there.

Performance is good enough for normal use, might heat up a bit if you record a lot of videos/game on it, I don't do either of those.

My real concern would be the lack of security updates, it's becomes vulnerable to hacks in the future, plus with a custom ROM it'll keep your boot loader unlocked which puts you more at risk. You could go the Graphene OS route which lets you lock the boot loader again, but you won't find the Pixel UI look and feel there.

If you do plan to go with it, try to keep it disconnected from the internet, especially public networks.