Cold water diving requires more exposure protection, hence you need more lead to get down. That requires more lift in the BC itself. One preferably that does not involve excess amounts of inherent buoyancy from useless padding and places that will trap air in the unit itself.
Cold water diving could also mean you are in locations where it is possible to encounter things like rocks and wrecks. Not to mention the abuse a BC can take when setting up on beaches, rocking boats, and regular exposure to saltwater. All of that takes a toll on fabrics. The lighter the travel BC the lighter fabric that has to be used. So it stands to reason that lighter fabrics are less resistant to really harsh conditions.
I don't know all of the brands you have in the UK. I know there are some we do not see over here as well as ones we have that you may not see much of.
My recommendation for cold water diving in heavy exposure suits in tough conditions that will have enough lift and still not add a bunch of inherent buoyancy you need to adjust for - A Back Plate and Wing set up with a steel plate. If you'll send me your email via PM I'll send an article I wrote that goes into considerable detail. But I can't PM it or post it here. It's too big with the illustrations.