They seem quite comparable in terms of features. The way they do relationships is a little different though. Sqlboiler is a little more ORM in its approach with relationships- it adds methods to retrieve relationships and it adds optional fields to its models. Jet on the other hand expects you to write out a type-safe join and then will load relationships into your struct automatically if you define a struct with the appropriate fields. I prefer the Jet approach- there's not ORM, just SQL and something that loads SQL results into structs. There is down-side that the loading into structs is not fully type-safe once you write custom structs rather than use generated models although I am not sure if that is even possible in sqlboiler.

sqlboiler shows a lot of examples of using strings for queries which is odd because they seem to support type-safe queries as well.