Cover bands are crap, thats what Dj's are for, at least dj's tend to put a bit of a spin on the songs.

Any cover band ive heard is allways shit, very few of the 'musicians' know music at all and probobly learnt the song off tabs, i wouldnt mind cover bands so much if they did a cover of a song, but improvised a bit, or extended the break(s) or just put their own personal twist to it, theres nothing great about copying something else.