WOW!
The Acavella Opera stirrups are a revelation 
Thank you, Emily!!
I tried them first on my dressage saddle and holy cow; they put my leg in a MUCH better position for aiding, my feet were immediately more comfortable (I have REALLY effed up feet with no arches, bunions and hammertoes), and my toes were able to “flex” better; the stirrup cradled my foot and allowed me to keep my toes forward, effortlessly.
It had an immediate positive effect on my leg effectiveness.
I put them on my jump saddle on Sunday (it took me no time to get used to them, fortunately - they felt like “home” from the get-go), and it was amazing; leg felt more secure and stayed put with no effort. My foot was more relaxed and I could feel my toes, everything just stayed in place without tension. Not to say that my leg position is problematic, LOL, but these stirrups helped keep everything balanced without me having to think about it. My one issue is with my left leg: it tends to want to slide back a bit - in both saddles. I usually make a conscious effort to fix this but the stirrups made it simple to even things up, and it just FELT easier!
I give them two ENTHUSIASTIC thumbs up!!!