I like Porkbun quite a bit but sometimes Namecheap is cheaper or it’s easier to just add to that account.
I think I can proudly say I’ve never used GoDaddy as a registrar, but I’ve been with some bad ones over the last 20 years so I can’t claim full moral high ground either.
But Ted's comment implies you can register .is through Namecheap. I wonder how/if they get around the Icelandic NS host problem.
I believe Namecheap offloads some of the info for .is back to ISNIC. The only reason I don’t do it under Namecheap is that I’ve had the ISNIC account for 11 years and it’s easy enough to get my annual email reminding me to renew, but I was able to get my friend’s registered through her Namecheap account without issue at the end of last year.
DNS service for my .is domain is handled by AWS Route 53.
It's been so problem-free that I couldn't even remember the provider's name -- I had to WHOIS my domain to figure out who was hosting it.