Taking the Bunks Vs Rollers thread, and all the other trailer related discussions over the years into consideration, here’s my spec for my ultimate trailer.
In no particular order:
Two speed reversible Electric winch with manual handle
Twin axles for anything over 6M Boat
Big, wide, jockey wheel
Disc brakes (with auto reverse of course)
Fixed waterproof light clusters
Built in tracking system
Tie down points
14inch diameter wheels with 8-ply tyres
Twin spare wheels
Built in spares/toolbox with bearing change kit.
Built in jacking system
Bearing buddies on the outside of the bearings
Stainless steel sleeves for the seals to seal to on the inside
Stainless brake cable and Bowdens
Replaceable stub axles, not welded in ones.
Stainless steel fixtures and fittings
Sliding launching trolley as Bedajims design
Rollers on the launching trolley
Bunks on Hydraulic rams that raise up to support the hull once the launching trolley is in position on the main trailer.
Trouble is all of the above would weigh so much there wouldn’t be much of a big 4x4s 3500kg towing limit left for the boat itself.