I have a Speakman Anystream, bought it after using one at friend's or hotel (?)
Mine is like the ebay model with the plastic and o-ring restrictor. I pulled the o-ring and broke away the plastic ring, so it's a full-flow model now. I've tried others, including a cool vintage Water Pik massaging head and always go back to the Speakman. We have 70+ pounds of pressure in the house most times and you almost cannot stand to open the valve completely, it's too strong.
Some of the ebay prices are astounding. Wow.