Step 20: D) Showerheads: Choices
The most intensive effort to develop a low-flow showerhead that offers an intense spray without too much cooling seems to be the work done by [www.bowlesfluidics.com Bowles Fluidics] on the Delta "H2O-Kinetic" system, which Building Green named one of the "Top 10 Green Building Products for 2006". It's available in an adjustable 1.6 to 2.5 gpm version, model 75152, from Amazon for $30, or in a fixed 1.6 gpm version, model RP46384 for about $35 from several sources, including Faucet Depot. I bought one and found that it does seem to maintain the temperature well, and it delivers a really intense spray--I'd call it more like a blast. If that's what you are looking for, it's a great choice.
Personally I prefer a somewhat less forceful spray, so I went back to a basic plastic 2.5 gpm showerhead, which doesn't aerate much delivers the water in coarse streams that also don't cool the water much, even though a lot less engineering went into it than into the H2O-Kinetic system. The one I have (second picture) is labeled Masco, which is the name of a company that owns lots of plumbing brands but as far as I can tell they don't make this one anymore. But it's nothing special. Similar ones are available for a dollar or two.
Some other options worth checking out:
The Niagara non-aerating showerhead advertises similar temperature advantages, at 2 gpm, and is adjustable from a "rain-like" spray to a more intense massage. It's available from EFI.org in white
for only $5 or chrome for $6.
Holiday Inn Express did extensive research on consumer showerhead preferences (according to this article) and is so proud of their chosen Kohler showerhead that they sell it in their online store for $80. It has three spray settings, one of which is aerated. Its 2.5 gpm rating isn't super low, but the endorsement of 7,000 testers and the flexibility of several settings to find ones that you and others using your shower like might make it worth $57 from Amazon (It's the Kohler Forte K-10284).
If you have a system like the foot pedal control to shut off the flow easily, it's not as important
to have a low-flow showerhead. But it does still matter that it doesn't chill the water too much, and that you like it!