I think the real question isn’t whether to adopt Kotlin or not. The question is WHEN, and HOW MUCH to adopt.
There are definitely a few people on our team that think that as well. I personally think that Kotlin and kapt have more to prove first. That said I think it is definitely trending that way. I’ll be interested to see if in say two years I look at this article and most the case against Kotlin I made here doesn’t even exist anymore.
Regardless lots of teams (like Pinterest!) decided the benefits of Kotlin already out weigh these costs and went ahead with it. That’s really the take away I’m hoping most teams get from this, if these objections don’t outweigh the benefits teams think they’ll get from Kotlin, they probably should consider going ahead and adopting it.