I bought a Derby house heavyweight stable rug at Blenheim. It is identical to the Mark Todd ones (only much cheaper) and seems to be a lovely rug. Fits my big shouldered horse very nicely - spot on sizing.
I bought a robinson's heavy stable rug last year, good quality (for the price) but just a little tight around the shoulders (even though my horsey has HUGE shoulders, would probably fit others fine) and not overly deep around the tummy. But it was £29 so cant moan too much!
Derby house turnout rugs are great, mine have been cleaned are ready to go again for this year, I've not had a rug last more than one season for years. Can't comment on their stable rugs but if the quality is similar to turnout rugs, I would definitely buy one.
Robinsons rugs from what I have seen are no good, they dont last and quickly stop being waterproof and if you have a more destructive rug type it lasts only weeks!
I bought a Robinsons rug recently. My horse is between a 6'3'' and a 6'6'' sizing, I bought the 6'3'' as I prefer his rugs to be slightly tighter as he tries to take them off! The 6'3'' was TINY! Well, it was only slightly tight length ways, but it was like a mini skirt round his sides, and I had the belly straps on their longest length and it was still very tight, and this is a skinny TB! The 6'6'' is only slightly better. I bought a Derby House heavyweight full neck turnout last year and I really like it. Its attractive and looks well made and wears well.