I agree 20 is not much these days
Have a desktop server, 3 laptops, 4 tablets, 2 phones, 3 cctv cameras, 2 tv, sky box, weather station, slingbox, apple tv, camera, 2 drives and a few kitchen appliances.
A few tv connected devices (that I'm normally testing) and a few other tablets (that I'm normally testing).
Have added about five friends and family to the network with their tablets and phones.
Just about to add a Greenhouse monitor
Hopefully will have a chomecast soon, when its officially launched in the UK
Then of course there is the sky wireless booster.