I have to admit to still using my 400cm 30% carbon Windwing (Dynafiber) for my older 4.2 and 5.0 sails. Even though I bought the mast back in 1995, it has been an awesome product. I used Fiberspars for many years after retiring the old 400 around 2000 or so, but I been obliged to bring it back to life in 2005 due to mast breakages. Because it was the recommended bend curve for my sails both then and now, its viability has been without flaw, although it's a bit stiffer due the luff shape of later sails. Nevertheless, it performs incredibly well.
Also, I've had great luck with a 430cm 75% carbon Fiberspar. I've had the mast since 1999, and it's been a great product that's earned its spot in the van.
However, I'm using new 100% carbon RDMs for all newer sails all the way up to 490cm. The newer masts are totally right and more durable, and I'm good with my outlook for the future. The current performance is simply right on.
Really, I think that I'm better prepared for the future than ever before. I'm definitely stoked!