There are quite a few things in this sport that, IMO, have more to do wtih marketing than actually giving you what you pay for--but string materials aren't one of them.

The high performance materials are much stronger and more durable, most have a lot less stretch/creep than dacron, they will generally reduce handshock, and increase performance.

That being said, there's also differences in how the string is made. A well made dacron string might work better than a poorly made FF type string.

My personal favorite is Dynaflight '97.

Chad