I`ve had an Ifor wiliams GH126 (12`x 6) earlier on this year, they have just recently introduced them in the UK, expanding the original GH range, mine was destined for Denmark where they had ben introduced before the UK, but was part of a cancelled order or something, sold by the factory dealers.
Just like other GH trailers but 8 inches wider and a couple of foot longer. The extra length is behind the axles so a digger will sit over the axles like the shorter plant trailer, or the extra length can be used for a more balanced load when carrying other stuff, I find a plant trailer nose heavy as the axles are at the back, where the extra length on this, helps.
I`m happy with it, nice loading angle, plenty of lashing points, the galv finish is OK, some I`ve seen where a bit lumpy looking, It`s got 13" wheels with the chunky looking tyres and seems to travel on softer stuff OK.