Pros/Cons of Same Length Speaker Cables?

Like many others, my amplifier, cd player, rack, etc. is off to the side rather than between the two speakers. This means the cable length is different for each. I've heard some (dealers!) say the cable lengths should be identical for both speakers. Aside from the cost issue for good cables, isn't it bad to have too much cable coiled up behind the rack? Why have identical lengths if it means one of the speaker cables has more than 6 extra feet coiled up? I know that resistance can be an issue, but is this really an issue with one cable at 16' and the other at 9'? Thanks in advance for your advice
Another consideration, even if you ignore the possibility of performance loss, is resale. More people than not, expect that a pair of interconnects or speaker cables will be a matched length. Personally, I have not found a little extra wire coiled up behind one speaker to be any worse than the difference that exists in the lengths being different. Many times too, the shortening of the length in only one of the pair of wires, does not get you much in the way of dollars saved. Just some things to consider, you must decide what is best for you.
In my experience depending on the cables, length may affect the sound. If your cables are affected by length, then the sound will not be balanced and/or may not sound the same. Another reason to get the same length.
Speaker cables transmit power from your amps. The cables are in fact acting as capacitors, that is they store power which your speakers will draw on during those demanding passages in the music. Makes sense to have both cables the same length and a minimum of 8 feet long.
Absolutely cables should be same length, would you drive your car with different size tires? Cable designers spend much time with cable conductor design,winding to preserve time allignment of music signal! I must disagree with Hiwaves....the shorter the speaker cable, the better the sound. If you have equipment rack off to one side, it would be cheaper and sound better if you put amp between speakers with short cables and ran long interconnect back to pre-amp, especially if balanced interconnects can be used. Check prices for 12ft interconnects vs 12 ft speaker cables, much cheaper....regards Sam
I must qualify above post by saying it all applies if you have good equipment and cables......if we are talking about Monster Cables and generic receiver then that is another story and you will probably notice no difference....
Avoid coiling the excess. Speaker maker KEF recommends bundling the extra wire in concertina fashion, that is, fanfold like the bellows on an accordian.