I do, I use Amber and sign in with NIP 46. However, I do cheat by also using alby and nos2x. NIP 46 has real usability issues related to latency, otherwise I think it would be ideal. I do want to dogfood it though to get the UX hiccups related to dealing with latency out so that we can onboard people onto multisig bunkers. This is the whole motivation behind welshman's thunk system, which optimistically updates the local database even before signing events.