@PeteS - Finding this an interesting debate, logically every song by every artist was never heard once upon a time, hence why should your good song be any different?
This is a just my opinion for general debate.
I try and avoid playing just covers live for many reasons:
1. I'm not them, I'm Me.
2. Why bother playing someone else stuff live when you can play your own?
3. How do you know that the audience will know the cover? I played "Independance Day" by the Comsat Angels at an open mic night once, nobody knew it, might as well been my own (btw I was on the drums, and a couple of my students, one was my boss, were on the guitar, I was laughing all the time, What a gas!) - got the standard polite ripple of applause, that everyone who was unknown the the local got. (The regulars got the predictable rapturous applause for Sweet Child o mine and Red House etc. that they churned out every week)
4. I'd only play a cover if I thought I was bringing something different to it, (Independance day was much more In your face, no organ, just raw power that I felt it lacked) I'm not into trying to recreate what they did, it just seems pointless to me, unless you are making a living out of it, like the Bootleg Beatles etc.
You know when you release a song here, and everyone loves it? well there should be no surprise then, when you come to play it live and everyone loves it out there.
The other thing I used to teach my students was how too perform, how to really deliver your song with passion, this makes a difference to the audience, a limp delivery is a missed opportunity, if it's your song and you believe in it, the audience will know...
Put yet another way...You take ages to write a song, perfect it, record it, produce it, release it, practise performing it until you are proud of it, then off you go and play live with someone else songs, Why?
In all honesty, I think a mix of your own material and a well arranged covers that fit the set is a winning combo (you see it often at top band's gigs), something off the wall, such as a Reggae version of Glenn Millers Pennsylvania 6-5000, or an acoustic Bossa Nova version of Motorhead's Ace of Spades, something to cause a reaction...
I reckon
@PaulyX could play a whole set of covers I wouldn't know any of 'em, such is his huge knowledge of bands, so why not play your own stuff.
Rich