Years ago I started looking at the new shower heads that had the flow restrictors in them. I figured out how to remove the flow restrictor and rather than a flow restrictor in the shower head, I put a shutoff valve between the wall and shower head. That way I can get a real blast of water when I want it, and use the valve to restrict the flow when I don't want the full "Hollywood" type shower.
Often, all it takes is to either pull the restrictor washer out of the shower head's supply, or use a Dremel type tool to grind open the restrictor plate so there is more flow. I now have a 10" rain type shower head with enough flow that it will damned near drown someone. Between the unrestricted shower head, and an extra large gas water heater, I have yet to run out of hot water during a Hollywood shower.
(for those who don't know, an unrestricted shower with all the hot water you wanted was called a Hollywood shower). Normally, it was required that you use limited water to wet yourself down, you later up, then you QUICKLY rinse off and get out...no lallygagging and enjoying all the hot water.