I've used a regular pillow
"I've used a regular pillow between knees for decades before buying this. The velcro strap on this is convenient. Yet, after many nights I don't know how to use this product pain-free. Legs comfortably bent means the groove seems out off place; Moving it makes my knees on one edge or the other. I end up alining the groove on calves (vs thighs. ) I actually wake up with sore or even cramped calves because of the sideways leg angle. my ankles are together yet knees spaced far apart. Well, I might be too short or built some other way so I can't use this product. It's soft texture, doesn't bother nor relieve me when i'm hot, the velcro doesn't poke & stays put while I spin in place all night. I don't think its overly firm or unfirm. My only yet major issue is for either size or shape, I just can't use it."