I have debated on whether to use a fancy background on my listings, and have opted not to so far.
I find many of them to be annoying and too busy, especially when combined with all kinds of other bells and whistles (bright colors, things flashing, or DARK backgrounds with dark text that is nearly impossible to read.) Plus it costs extra to use them!
Some people have noted that for those with slower PCs and connections, listings with fancy backgrounds and other stuff might take longer to load. I suspect the ones that eBay offers for use are not likely to cause those types of problems, but I'm not certain.
I do wonder if a fancier-looking listing brings in more bids/bucks, however. Sometimes those simple little mom-n-pop listings are the ones that have the better deals... the people that can afford the big bucks for the more expensive listings likely know what the value is of every last widget they sell, and are not likely to be selling them for much of a deal.
Ok... I think I'm rambling now... bye for now!
Dag