I have a fairly average router which was free with my broadband (Sky) - I think it's a belkin one and is about 3 years old now.
We have an iMac, Ipad, couple of DAB/internet radios which also act as music players (ie stream via wifi from iMac) plus an apple tv. Also have iphones linked in as well. So the wifi is getting a fair amount of abuse day to day.
What would be advantages of getting a new router? The current one freezes every now and then (but not more than once a month so not particualrly critical) and needs turning off and then on again (in true classic IT person fashion!). But it's fairly functional.