Not many. The only deal breaker I've hit is the inability to return multiple result sets with the built in SQL package.

I haven't missed generics that muc, but it would be nice to be able to do things like sorting without implementing a sorter interface.

I can live with this though because everything I've written in go so far had been easy to reason about and most importantly it "just works". I can read anyone's code an understand what it's doing. Can't really say that's been true in the 25 years I've been doing this.