If a hefty repeatable 30# tamp is what you want, then this is the last tamper you should buy (assuming you like black or red color).
Positive Product Points
calibrated 30# click (subtle NOT audible few feet away)
heft (58mm convex weighs 478 grams-16.85 oz)
available in flat and convex base
anodized aluminum handle (has multiple small circumferential lines so that there is tack to handle - this is NOT visible on picture on espro website)
great single sheet instructions on makiing espresso in pictures (e.g. shows Staub tamp method and single tamp)
Negative Product Points
based on price alone ($90) expensive compared to other "high end" tampers (e.g. Reg Barber) BUT I am unaware of any other tamper with calibrated click
available in only two colors (black and red handle- and for 58mm black only
no multiple color options for handle (besides red&black) and no multiple base options (e.g. 0.1mm variations with Reg Barber)
cheap looking packaging for at $90 tamper (white cardboard cylinder)
Overall tamper is a very personal choice (e.g. fit to one's hand size) and one must try out tamper before buying (unless you've got money to afford multiple tampers).
Like some other reviewers who own this tamper, I do NOT feel this tamper is a training-only device. It provides consistency- repeatable 30# tamps. Like volumetric dosing for espresso machines, there is one less variable to focus on. Given that achieving 30# tamp is now "automatic" some may believe there is less input to the espresso preparation. To this I would say absolutely no. This tamper will not correct if your tamp is not level.
I really like the heft and feel of this tamper. Some might think this tamper is too heavy but I like the weight. Especially appreciated is the anodized aluminum has multiple fine circumferential lines that gives the handle tack.
IMO this tamper would be perfect if there were more options like with Reg Barber (e.g. more handle color options, more base diameter options).
The negatives above really are not negatives but in the interest of helping others I mention them (car analogy: kinda like owning a 911 Turbo and finding faults with it). Do not get me wrong, I love this tamper as it suits my needs and hand size.
Chris Coffee is excellent as too numerous to count others have mentioned elsewhere on coffeegeek.com