what is weird is that you get less latency using wifi. WiFi only works one way at a time and has to take turns with all other wifi conected devices. It could just be that the switch on the hub is terrible.
Or else the ethernet adaptor is badly setup or poor quality. What are you connecting to the Hub, is it a pc and if so what os etc?
when you have a mo, could you try opening a dos box and pinging the hub at 192.168.0 1 using an ethernet connection and then using wifi.
on the whole as long as you have cat5e or above the cable shouldn't really make a difference unless you have a faulty cable.