I can't say anything about the voltage & plug differences, or even if you can get the proper equipment to use them in the UK.
However, about the filter itself I'm very happy & satisfied with my Aquaclear!
I'm using the #30 filter on my 15 gallon tank (58 liters) and it keeps the water very clean. One of the best things about the filter IMO is being able to adjust the flow.
PS: Did you order the stuff you need for filter changes with the filter?