I have tried several similar wireless set-ups, where the chime has been battery-powered and they all seem to eat batteries very quickly. This means that you end up without a doorbell, just when the postie comes with an important package!
So I liked the idea of this, as the chime plugs into the mains - but doesn't take up plug space, as you can plug something else into it. In theory this seems a good idea, but in practice the unit is so wide it won't fit into the space on most plugboards, for example. This limits where you can place it - but in the end, I did find a suitable place - although this might be a limiting factor for some people.
The bell-press is a bit flimsy and when I was trying to get it open to put the small battery in, the catch looked like it could break easily. This would be a problem and some might prefer a more substantial unit?
The other thing this unit addresses is the problem of "phantom" bell rings. With so many remote units about, it becomes possible for neighbours to set your bell off and this has happened to me - it can be very annoying when you are interrupted for no reason. The idea here is that there are 16 channels and if this happens, you can just change channel and most people won't have 16 neighbours within 100 metres. So I think this is a good idea and a big plus for this unit - along with mains-powered chimes, which are loud and clear.
Overall a reasonable package that is good value and which works well enough.