Whether it be for drop shot , shaky head , finesse swim bait , or wacky worm - what is your current favorite #6lb. to #8lb. FC line for a 2500 / 3000 size spinning reel ? *I'm a braid + FC leader guy for spinning reel applications ,  however I do see potential for smaller diameter ( .010mm line diameter or under) straight FC line for spinning reels . Tatsu is a bit expensive , so my focus is in that "next tier" of FC lines  below Tatsu such as Berkley Trilene 100% FC , InvizX , P-Line , Yo Zuri and possibly a few others I may have missed that handle well , don't turn "milky" in color , have low stretch and decent abrasion resistance.. I'll use mono backing on the reel first and then a top shot of say 75 yards of the FC line on top. Lastly , KVD line conditioner is on deck to use if need be .  Thanks in advance for replies - hopefully I am not asking for too much .

If it isn't Tatsu on my reel - it's gotta be InvizX

7 lb Sniper

I've had good luck with Daiwa J-Flouro and Invizx in the 4 and 6 lbs range. Both are very similar.

Sunline Sniper is great. I've heard good things about InvizX. I think InvizX may be a little more subtle from what I've read. Sniper, I believe, has less stretch and more abrasion resistant. If you're talking straight fluoro on a spinning reel, InvizX may be the way to go. 

I would also say Sunline Sniper, been very pleased with that line.

Sunline Sniper #7 lb. and InvizX #6 lb. are both under .010mm , so casting should be about as good as it gets on a spinning reel .

When I troll 100' behind the boat with 2 very different rods ? 1 is 6 # braid. Other is 60 # braid. Both are set up with a hang down weight & identical lures. Both weights are just ticking weeds and the lures are 3' above the grass or bottom.  Both of the lures get hit at almost the same time. There is no noticeable favor to the  smaller size line.   Sunny or very rough dark day.    When they are hungry ?  It is like a pack of wolves attacking.  2 fish on a lure do happen.