Great point as I too have found that, especially when doing covers, unless you have availability of the same musicians/tracks who did the original and the talent to do a spot on impersonation of the lead performer it will still be a copy, hopefully a good one but a copy none the less. While on the other hand you do the cover in your own style or even someone else's style it allows you some leeway in the audience's ear and mind.

Basically an audience will be more forgiving and may actually love what you have done with one of their favorite songs with a different arrangement, while if you try to copy it note for note and instrument for instrument it will at best be a lesser rendition of that same song.

Later,