I purchased this device to find out how much it costs to run an oil filled electric heater, over a whole day. It does exactly what it says on the tin. The heater costs far less to run than I had previously thought, and now I have no qualms about running it over the course of a cold day.
Regarding the screen's readability; this is easily remedied with a short in-line extension lead, which will allow you to pick up the device to read it, at whatever level you feel comfortable.
This is a reference device, which is useful for such applications as I described above. It doesn't make sense to use it as a permanent fixture as it does draw a small amount of power itself 0.5W. It is an excellent value device, which provides an ideal way to ascertain accurate energy usages over time.