i have never liked putting swivels on my line, but i can see how the fireline adds sensitivity.  what size swivels are you using?  also i'm usually to lazy to tie that many knots 

I thought of the blood knot, too Rob.  Do you use this sort of set-up with the knot?  Does it come apart, at all, as some braids do?

For fishing deep, I too use the Uni knot on line to leader for crawfish type presentations.  Otherwise I am a big fan of Roboworms on a dropshot rig.  I keep the bait from 4 to 8 inches above the weight, this has worked better for big fish in the fall, than the normal 15 to 20 inches I use during the summer.

I do not use a swivel with fireline (et al), but will use it occasionally with copolymer, mono etc when I have to due to the constant twist from using the spinning reel, but I use as small a swivel as I can tie up. 

I am confident with this presentation...fwiw

BillB

Usually 10-12 feet in case a break off. Leaves me some line to re-tie. Saves on mono too if you like to buy expensive stuff and cuts down on re-spooling time.