It is really good advice, I am a wedding planner in Jamaica and chair covers are always the best way to go. most persons tend to use white with the ties- backs of their choice, something that will match their colour scheme. this tends to give the area a really elegant look, if there is a choice of centrepiece over chair covers,I would personally go for the covers
At first the cost for covers looks expensive, but remember you have to live with the photos/video and they can be cruel :)
I would also suggest using a local vender, on your wedding day you do not want the additional hassle of ensuring the persons you gave the task of putting on the covers either forgot or just could not be bothered. I have seen this too many times. your wedding day is supposed to be a stress free day to be fondly remembered