As with any Philips Hue device, these are not cheap. That is not the point of this review - It's just an acknowledgment of the ecosystem. If you don't like it, then don't buy Hue. If you have Hue, it's just a part of the cost of enjoying the most advanced and versatile system of lighting that currently exists in the market for most people.
Regarding the Tap Switch - This is one unique device, and it is splendid for what it is. To define that exactly though, is perhaps more easily done by saying what it IS NOT:
It is NOT a normal switch. It can be wall mounted, but isn't best used there all the time (unless you really like having a weird hockey puck on your wall, in addition to the hockey puck that would be a smart thermostat). It isn't the super-program-it-to-do-a-billion-things sort of smart switch with double/triple-tap options. This is not a delicate device that will respond to the lightest touch.
What this is though, is a switch that can handle a few programmable scenes, is powered by your button press (and thus requires some effort to push, with a tactile click - Also won't register multi-tap since it is a deliberate and slow click) and will never need replacement batteries since it has none. It is great for placing somewhere and not worrying about it, like on a table runner for the dining room, or on the nightstand for a bedroom, or on the desk in an office.
A couple examples of where these are being used in the house:
Our dining room has a series of BR30 color bulbs, so we have buttons on this switch set to a seasonal pattern (that I change every few months), a bright, a dim, and off. The switch sits beside whatever decorations are on the table.
In the bedroom we have a number of reading lamps that run on Hue schedules to turn on in the evening, and dim as is gets later. The switch has a magnetic dock that I've made for the headboard of the bed. The buttons are set to full brightness, dimmed, only one lamp (for when I'm reading but don't want to disturb my wife), and off. We have one at each side of the bed, and each switch has been set to turn on the lamp on that side only, so that it's easy to transition to as much or as little light as we need, and we never had to worry about accidentally pressing a button that is overly sensitive as we fumble in the dark while sleepy. And no worrying about batteries - These will work as long as there is power to the lights and the Hue hub.
My rating is 5/5 - As with any smart switch, it is not for everyone, or for every use, but there are some great ways to use this that simply can't be replicated by any other style of switch.