Pros and cons for both when towing long boat?

Depends on weight of boat/trailer when connected to the vehicle (GVWR). Will have no effect on the boat, only the tow capacity of the vehicle.

Have you towed a gooseneck before? I prefer them, truck feels more balanced, can back into some tighter areas, shorter length overall.
cons, can’t just call anyone to move your boat if your truck is down, may have to get the truck closer or deeper in the water at some ramps.

I have not towed with a 5th wheel gooseneck but with the Maximus being 45' im curious what the big guys prefer. Seems like turning is easier with 5th wheel and that might come in handy. The hauler who delivered the boat said go bumper pull if
I replace trailer.

If your truck breaks down it is way easier to find a friend with a bumper pull than a 5th wheel or goose ball. If you are going to tow a lot i would go with the goose ball

Bumper pull all day. The proper size truck and balanced trailer absolutely no problems. Plus you loose the storage in the bed with the gooseneck.

I pull my 45 on bumper and no problem at all!

Have pulled both many of times. I prefer bumper for a boat trailer. All the weight of a boat (on a proper balanced trailer) is at the back, so tongue weight is not really an issue. I also like being able to have my toneau cover closed for security and mileage, which you cant do with a goose neck.

Tonneau cover closed for mileage...while towing 15k? Lol

I thought MythBusters do one on that and found it didn't make a difference?