I’m a fan of Horsewear mostly because their blankets are “horse shaped”. The fit is so much better, the blankets stay in place and don’t rub the haircoat. I did have a Rambo which lost waterproofing within the 3 year warranty and after jumping through a few hoops, I received a replacement blanket free of charge. So be sure to register your Horsewear items according to the warranty directions when you receive them and even take a photo of the receipt. I am using no-fill Rambo Original with leg arches and Amigo 1200 (I like to have a spare waterproof outer shell). The liner system is terrific, stays in place really well. I have the “vari layer” liner (450g) for the heavy weight and it seems very comfortable for my horse on the coldest days, For temps between 30-40 degrees I use a midweight (200 gm) Horsewear liner.
In contrast, when my Schneider blanket was torn within months of ownership, I discovered that the “warranty” meant that a roll of breathable waterproof repair material was mailed to me free of charge. Also, Schneider blankets just don’t fit as well, it’s like hanging a tarp over your horse. The “v-free” option often leaves an open pocket at the neck that can collect a lot of rain or snow.
My only experience with Smartpak is a fly sheet which wasn’t the greatest fitting item, as expected since it was less expensive than other brands. That said, Smartpak is a great company to work with.
Blanket fit matters most when the horse wears the blanket 24/7 for weeks at a time. I’ve had a horse end up very sore around the withers area from a poorly fitted blanket, the neck hole was too large and the blanket put pressure on the wither. On the other hand, if blanketing is only done occasionally for wet days or unusually cold conditions, or if the blankets are removed every night while the horse is stalled, then perhaps fit isn’t as critical.
