Block connector is a simple and effective way of connecting your panel to its wiring harness. It has the advantage of only needing simple tools to work with it. It is also great when you only want to connect or disconnect one wire at a time.
Robust and long lasting, not water proof but water gets out as easy as it gets in so great when under cover.
Main disadvantage is it takes time to connect or disconnect the whole thing.
This is the one that I choose. Snap lock connectors give you the convenience of being able to connect up a number of wires at once and if the wiring gets wet it will dry out again once conditions allow.
The main disadvantage is that you need a special crimping tool to attach the wires correctly. Though it is possible to use small pliers to do the job.
Superseal connectors can be the best choice for connecting up the wiring on your boat. if they are put together correctly using the correct tools they do a magnificent job. However there are a number of things to think about: