1) Could my present setup be improved in some way?
The rule of the thumb with wireless is that best possible performance is obtained when the wireless router and wireless devices have line-of-sight with each other, or they are in close proximity to each other with a minimum of obstructions in the signal path. So, relocating the Sky router might improve things substantially depending on where you use your wireless devices most often.
2) The Sky router gets a very bad review and is way behind the competition. Would replacing that help my problem and if so recommendations of replacements would be appreciated.
Without more testing, it is not really possible to say whether your performance is being limited by the Sky router or the Home Plugs. Connect your computer directly to one of the LAN <--> Ethernet ports on the Sky router and check the download speed that way. Then, connect your computer directly to one of the home plugs in the location where you normally use your devices and check the speed at that location. Report on your results.
3) would a wifi extender, solve my problem?
If the Home Plugs are working well in the area where you need more wireless coverage, then adding another router at that location to the Home Plug and then configuring it to provide more wireless coverage in that area might help your performance. It all depends on your Home Plug tests in 2) above. If the signal at the remote Home Plug is slow, then the remote wireless router that you install will receive a slow signal and little to no benefit in performance will be realized. On the other hand, if the remote Home Plug exhibits good speed in 2) above, then you will have stronger and faster wireless coverage if you connect a remote router to the Home Plug.
The bottom line here is that if you are thinking of an Apple router...or any other router....its performance will only be as good as the signal that it receives through the Home Plug network devices that you have installed. Almost without exception, connecting devices using a wired Ethernet cable is going to yield better results than a connection through Home Plug devices.
