I am looking to replace my main sheet, what line has been working well for most people, currently it's yale vizzion.

New England V-100 is the top shelf line for mainsheet applications as far as I'm concerned.

If you don't feel like spending 2$ per foot or more then try trophy braid or new england bzz line. I use the bzz line for my spin sheets. The trophy can be tapered (no, doesn't look as sweet as the dyneema/vectran cores but works fine). I am using trophy now for my mainsheet because although I spend a lot of money on somewhat silly stuff, I can't seem to bring myself to spend that much on lines (generally I look for under 1$ a foot). There was an amazing sale on a certain store recently disounting D2 and V2 down to 70c a foot though, so watch for clearance stuff). IMO The only line that shouldn't be allowed some stretch is the spin halyard and tack line. If someone can point to any serious/real world/non-olympic level advantage of 2$/ft vs .70-.80/ft I would love to hear it.

I'm a recent convert to any of the Composite single braids. For a "near" complete listing you can check Layline at http://www.layline.com/llf/cats/cord_05/Composite_gray.htm
I'm using Salsa for my Spin halyard, Apex for my Spin sheets (my wife/crew loves them...soft on hands, pliable, lightweight and they don't kink easily). Layline does not have listed, but does also sell Robline Racing sheet which is another of this class. I am using that as a mainsheet / traveler line with a piece of dyneema doubled over and spliced in for the rear beam traveler line tie-off. So far...I love it!! Mafiolli staretd this whole lineup with Swiftcord, but they continue to be the most expensive, and I have found all of them to be comparable, so I'd recommend finding whatever (of the single braid composites) is on sale and go for it. (and no...I don't work for Layline...)

I'm a big fan of the Robline "ice" for the spin sheet.

V-100 is too stiff for a mainsheet. I think you are referring to Dyneema Racing 2, Jake?
The "ice" is actually called Robline "Racing Sheet."
I like the racing sheet with spectra spliced to it.

Oh yeah, I'm in St. Thomas right now, on the beach, with a H16, a N5.8, and a Nacra 20, along with 6 of my good sailing friends. Man I love college...........

You brought your computer on the beach to go on the catsailor forums?

How about samson warpspeed, looks like it tapers easily.

Warpspeed tapers very well, but the poly cover doesn't take the abuse as well as some of the other products out there.

Dyneema racing 2 is the bomb. Joe, I bought the tapered salsa spin halyard from Krantz and its by far the best halyard Ive used. Dave Ingram put together a nice little line spec sheet, I think I have a link to it at the powergroove site somehwere, or he can chime in, Dave, you out there somewhere?
Mike,
I need some NACRA parts bro....Im calling you today, you around the shop?

PowerDave,

Give me a shout. I'm around here somewhere.

-Mike

Mainsheet: Conception spliced with Vectran (for the 10:1 blocks)

Spin Sheet is Apex with a 16 inch tail of Vectran attached to clew of spinnaker.

Spin Halyard is Conception spliced with Vectran.

Downhaul uses the Vectran in the 8:1 blocks then Maffoli Swiftcord for the 2:1 cascaded line that the hands hold. Total purchase 16:1.