My dressage trainer goes mad at me for using them but they are so comfy I didn't want to change. Zara Phillips had them on at Badminton dressage this year so that's ok by me. I did tell him and he raised his eyebrows
yep. i use them for everything now, one day using normal stirrups and my smashed-up knee complains all evening.
make sure you get the Sprenger ones though, as the cheaper makes aren't as strong (someone had one snap xc last year iirc.)
if you know anyone who's going to Germany, they're £40 a pair over there...
I have lax ligaments in both ankles and as a result twist and sprain my ankles a lot. These are the only stirrups I can ride in without pain after a decent workout during lessons.
Another benefit is they are harder to 'lose' if your horse does an unexpected sideways or spinning manouver (and I don't mean half pass or pirouette!!)