I replaced mine and it sounds a million times better. The stock tweets are too small and not very loud. The tweets I installed were about 40mm arround and an inch or so tall. I had to remove some of the plastic prongs that stick up off the stock tweeters back plate to get it in, and then glued it in place.

Also get rid of the stock capacitor, as it is set too high. If you are adding tweeters that arent part of a component set, but a new capacitor.

Heres a good chart for reference.

http://www.partsexpress.com/resources/xover.html