I have a pair which are ages old but have last so well. I am loath to get rid of them - you never know I may one day do XC on Chancer.
I bought them for Breeze following a cracked fetlock - despite being ancient she refused to walk slowly when coming back in work and jogged along and kept going lame.
Once she had these boots, she never went lame again and recovered to go hunting and XC full pelt again.
Also used them for XC on my second TB - good support but you should not leave them for too long a period.