With the possible exception of the oxygenics shower head, which is kind of a special device I think all shower heads sold in the US today have the ()*@#&$)(@!#*) Flow restrictors.
Back when I had a stick house I had a plumbing problem, Arterial sclerosis is a good description of it. Got to where I could pass warm water faster than the water heater. So one morning I said "ENOUGH" grabbed a couple of tools and my wallet, Took a saw to the outlet pipe on the water heater and removed the section that passed over the furnace It was 1/2 inch, Took it to Plumb Hollow hardware, (now history) which at the time still cut and fitted pipe and said "Duplicate in 3/4" They did.
Paid for it, came home and installed it,, Took a nice LONG (40 gallon heater) Hot shower.
Wife came home and went to do dishes.. She turned on the hot water and waited for the stream to slow to a trickle.. It never did.
Well, then we upgraded the bathroom, nice new tub and shower WITH A FLOW RESTRICTOR.. That lasted about 10 minutes. (Just long enough for me to find the proper wrench)