I'm definitely impressed with the sound ID. One time there was a cacophony of birds singing outside my house at varying distances, and the app was able to identify 6 different bird species within 30 seconds. All 6 suggestions seemed reasonable to me.
We sometimes joke it's hallucinating when it detects something unexpected, but often it was being accurate. I saw my first ever male Blackburnian Warbler a couple weeks ago after Merlin picked it up.