I have never had a spinning reel and am wondering when you use one, and what you use it for.  

I use a couple.

6'6 med-hvy avid shimano sahara spooled with 14# suffix braid for skipping docks

6'9 kistler LTX med-hvy with shimano symetre spooled with 14# suffix braid also for docks. I like to have a couple different setups ready if one doesn't work i'll try the other

7' med fast avid for drop shot, shakey head or tubes.

I use spinners for dinks and up to tarpon, If I target fish over 50# I use a conventional.

I use spinning tackle primarily for light weight lures and for finesse presentations.  My curent set up st croix avs66m paired with a quantum energy

For me it is the side of the boat that makes the choice which is determined by the wind since I fish into the wind.  I use spinning on the starboard side and bc on the port when fishing plastics and jigs under 1/2 oz.  I get a much better hookset on the starboard with spinning than bc.

I just use spinning gear all the time. d**n baitcasters, ive got a couple but nothing ruins a good day on the water like a massive birdsnest.

Anything under 1/4oz.... Spinning

Anything over.... Casting

I use spinning for everything.

I should add I rarely throw anything above 1/4 oz.

I'm a light tackle junkie.

Anything under 1/4oz.... Spinning

Anything over.... Casting

Thanks for ya'lls imput.  I have always used baitcasting, but figured I was in need of diversifying my gear.

spin reels for light lures and light lines... oh and catfishing (larger rods and larger line)

X 2

Anything under 1/4oz.... Spinning

Anything over.... Casting