Reply to headphones: sennheiser hd 280 vs. pioneer hdj 500 for DJING

Hey guys im in the market for a new pair of headphones, looking to see if i can get it locally if possible (hate paying shipping) and i'm stuck between the sennheiser hd 280s and the pioneer hdj500s. I love the look of the hdj 500s but the pictures make the phones seem like they're an on ear (pressing against the ear) instead of over the ear headphone, wondering if someone can clarify this! Also the sennheisers I have read have weak bass response and seem to be more of a studio headphone, wondering if they would be adequate for djing at gigs? If you've had either pair please share your experience, both seem to have great reviews all over but I would prefer an over the ear to an on ear (pushing against the ear) headphone !