Make sure the boots fit the horse; not all styles work on every horse
I had a Barefoot trimmer size two of my horses and it was a good thing -- I would have messed that up royally, left to my own devices
I have one horse that can wear the Gloves and they fit him like gloves.
There is no way this side of Hades and back Gloves will work for the other horse.
The other horse was fitted for EasyCare's Boa's. The Old Macs fit him but the arthritis in my hands wouldn't let me work the clamps. The Boa's have dials and I can work those much better.
The horse with the Boa's is the one that foundered so bad last year. He went out to a pasture every day in those Boas and part pads. They fit him just snug enough to where his hooves weren't slopping around in them. They accidentally turned out to be the best recovery boots I could have asked for.
As far as too much slop from the standpoint of founder recovery, I did try a new pair of Cavallos. They were so "un-snug", they literally set my horse's recovery time back by about five days. Based on that experience I would never buy them for trail riding, although some folks swear by them.
If you decide you like EasyCare, I would call the 800 number and talk to their Customer Reps. Those gals are fantastic and will patiently ask you the right questions and walk you thru everything you need to know about each boot style you might be interested in.
I didn't realize how lucky I was to have the Boa's fit Joker and also workable for my hands, until he foundered and I needed them for his recovery.
Hope this helps