I am about to take ownership of Merlin Rocket and looking for advice on best type /style of road trailer to purchase

sovereign are excellent, so are west mersea - just make sure you get big wheels and a well fitted cradle

Winders also do an excellent combi

In my experience the cradle on the Sovriegn trailer is positioned well and under a well supported part of the hull.  

With the West Mersey the cradle is further back where the hull is not stiffened and planks have sprung (wooden boats of course).

The upside is the WM is lighter at the handles (I guess it is because the cradle is further back, the wheels being a pivot point), I have both types, one for each Winder :-), for a long drag up mill bay, i'll slip the boat back 4 inches on the sovergein to lighten the load.

I have just sold my WM for the exact reason Bob has just mentioned plus, Alan have you tried to pick up your WM without the boat on it? Seriously nearly gave me a hernia the first time i tried!! My Soverign is perfectly balanced and was not too much of a problem at Tenby on the beach.

Strange, it really pulled Jack and mine arms off on Tenby, I might be a bit feeble but Jack is pretty strong. When you got your boat weighed did the trasom hit the ground when they put it on the scales in teh 'standard' position?

Not particularly, however remember my boat has no correctors so it is going to be slightly heavier at the rear than yours. Might be that the extra weight is all in the middle to transom?