Let's say (for example) that your spinning reel holds 110 yds of 6lb line.  If 20 lb braid has an equivalent diameter of 6lb line why wouldn't you put the 20lb braid on your line?  Chances of line breakage is reduced to almost nil. 

I know there's got to be a logical reason why this isn't a good idea but darn if I can up with one.  Anyone???

I do that all the time, except when I specifically want the stretch of mono, or the sinking properties of fluoro.

I believe several others use braid on spinning rigs too. The no memory property really helps.

EDIT: when I'm worried about the fish seeing the line, or need abrasion resistance (which is just about all the time), I put on a fluoro leader. The leader also helps when you get snagged; I don't have to lose yards of expensive Samurai.

I do that all the time, except when I specifically want the stretch of mono, or the sinking properties of fluoro.

I believe several others use braid on spinning rigs too. The no memory property really helps.

Well said.

Logically it is....but i fish where rocks and zebra mussels are.Braid line just won't work in that situation for me.

I do have one set up that has braid on it for pond fishing.

I use it a lot for those inline spinners..saves me tons of trouble with line twist on spinning reels.

Well, if I fished for peacock bass, I would too.  But throwing a dropshot for 2-5 lb average bass, I'll get more bites with 6 lb fluoro.  At least, that's what I believe.

I use braid on my spinning rigs.  Just add an appropriate leader.  Generally I use a fluoro or a co-poly leader on mine.