Currently, I'm with you on not switching from NameCheap, yet. But for me, it's just because I have too many domains and don't want to move them all to a more expensive service.
Transferring domains is such a tedious process when you have more than a few. Between the 60 day rules, auth codes, and the actual transfer process... not enjoyable. Though on the plus side, I've never had to wait more than a single business day, for any registrar, to complete a transfer.
Back to Google Domains: I won't be completely satisfied until I see Google,
hopefully, roll out their Material Design concept across their web services. I love Material Design. My one current issue with Google Domains is the boring interface. I actually find it to be lacking in comparison to other Google services. The functionality is there, but I want to see something more appealing to the eye.
Google's WHOIS privacy service is also something I'd like to see modified, though I doubt this will happen and I'm sure it's not at all a priority. In general, I'm not fond of these privacy/protection services that registrars offer to customers. I strongly dislike the fact that my information is being replaced with that of a proxy company based in New Zealand. The same goes for WhoisGuard, in Panama. I
hate it with a passion. The only registrar "doing it right" is Dynadot. They keep the owner's name in each WHOIS field while masking other sensitive details. At the very least, I like to see US-based proxy services (Name.com wins a few points for this). Regardless, I no longer use any of them. My information, no hassles.
Keeping in mind that it's "invite-only beta," it's pretty decent. My opinion really hasn't budged, and I'll still keep a domain or two with them to see how things change. I definitely understand where
@KH-FreddieA is coming from.