I've tried both, on occasion wired I may get up to 80Mbps but normally around high 50's. however my question would be, you obviously buy wireless broadband to be wireless, even with the hub right next to the laptop or iPad I still only get 30/40Mbps.
I think the issue is that from a sales pitch by Virgin it can deal with up to 100Mbps but does not necessarily mean you get it.
I am sorry you are having problems with wireless speed, there can be so many factors involved. We have some wireless guides that may help. Apart from that the connection is looking good, little bit of peak time traffic but not too bad.