Sensation is THE biggest event but it's so big because it's very commercial..

You can notice that a lot of persons in the audience are the average TMF/MTV watchers that go to their first event. Not the true EDM-lovers that come for the music... ofcourse they are there, but a minority I think.

DefQon has much more choice in terms of DJ's & stages so you can to whatever you prefer. Furthermore the atmosphere is totally different...
Sensation is HUGE just cause it's a football stadium filled with 50.000 people
DefQon is more close but stil very energetic due to the setting/location