It's pricey and utilitarian, but tamps very precisely and fast
Positive Product Points
It fits commercial baskets like a piston fits a cyclinder.
Negative Product Points
This milled solid steel tamper has a mildly curved bottom and weighs 520 grams. The top knob is about 30 mm across and fits comfortably in the palm. One can get a logo put on the knob. It is comfortable on the arm when tamping and clearly indestructable.
The best feature is it's tight fit to my Faema and Isomac commercial baskets. The tamper won't even insert unless it's perfectly vertical. This has two big advantages. First, I never get tamps that are sloped off to one side. Second, one press and a twist smooths the puck completely without the little swirls of grounds along the edges. All the gyrations of straightening out the tamp, fixing the edges, or doing four NSEW tamps are avoided.
An identically shaped tamper made of aluminum is also available at $22
Espressoparts NW has a first rate e-business outlet, and is worth a look when shopping for supplies. They also sell high end machines and grinders.