Sooo, I can weigh in with my experiences, having used the sheet (with neck) last week when we got INCHES of rain within a 36 hour period.
The sheet kept her pretty much completely dry (in the body), and she was clean underneath; but the fit of the sheet was such that I had to snug everything to its tightest setting - and there was still some “play” in the chest. IMO, it runs large in the front, bigtime!
Because it has an attached neck, it kept her dry anyway with only a bit of moisture sneaking in around the bottom of the neck piece - and she managed to get the top of her neck muddy (but she always manages this
)
She is not a “petite” horse (she is relatively wide through the barrel and has a long neck AND back - would never have fit a smaller size for that reason), but she doesn’t have a huge chest and shoulder; her dam (who I bought this sheet for) is broader through the chest so it will probably fit her better. The velcro on the neck could be grippier! It looks like with some use, it may lose its “stick.”
The coverage otherwise was good; the sheet has nice long sides and a generous tail flap, and I liked the shoulder gussets - lots of freedom for movement (maybe a little too much in my mare’s case!), but it seemed to stay put, so…) It will be interesting to check the fit on my other mare. She lives out, so the waterproofing will be put to the test!
I give it a thumbs up with the caveat: “runs large through the shoulders.”