I
was fishing with 30lb Spiderwire EZ-braid on my baicasting reel... but was very disappointed with it's abrasion resistance, getting bitten off several times from not-so-big chain pickerel, which, surprisingly, never happened with mono!
I recently got a new baitcaster so I decided to try fluoro - I chose 12lb
Vicious 100% fluorocarbon. I LOVE it! It's very sensitive, abit stiffer than mono, but not so much as to bother you or anything - and I have NEVER gotten broken/bitten off, even when hopelessly wrapped up in lily pad stems, forcing me to wade into the water to get my fish! It's strength and abrasion resistance is awesome.
I'm not sure if I would use it on spinning reels... it does have some stiffness, but I have not tried the lighter pound tests, so they may be more supple, but again, this is the only brand of fluoro I have tried so far. And like the other poster said, fluoro does sink, so it's not ideal for topwater baits, but for everything else, I'd say it's great. For now, I am still using mono on my spinning reels.
I have not yet given up on braid - I'd like to try Power Pro(this line company is actually owned by Shimano, one of the BIG dogs in rods & reels) - but I will NOT use Spiderwire EZ-braid
ever again.