To get an idea if this is going to save you any money first take a reading from your electric meter. I did this and found that overnight it costs me 5 units which equates to £139 a year in electricity used by standby!!!!!!
The night I plugged this gadget in my usage dropped to 2 units over the same time scale thus saving me £83!!.
Now all that is on over night is the large freezer and Fridge freezer and two digital alarm clocks and SKY+ instead of the above and these:
PC, Scanner, Printer, Wireless mouse and keyboard, PC Surround system, LCD Monitor, 2 TV's, Hifi, DVD, Scart Router, Modulator, TV sender, PS2
So YES get one or two.
There is however one problem if your appliance has a large transformer it will take up two slots on the unit. I got by this by using a small extension with two extrasockets on it and it works fine now.