The interesting implication of panspermia is that is yes, we would recognize alien life. I find this optimistic. Anthropocentric perhaps? Like a version of living in a slightly more sophisticated sci-fi show.
Thats assuming there is one single common origin for all panspermia. There could be multiple events and independent lineages. These are not mutually exclusive hypothesis because even with panspermia, life would have to originate somewhere to be seeded elsewhere.