The one I bought is a flotation harness as opposed to a suspenders. Its a U shaped vest; perhaps 5" wide and 2" in depth that goes over your head and has a Y shaped web back which is secured with an adjustable waist belt. Its light; a pound or two at most and at first try in the yard last night; with a wintewr jacket on and it over the jacket; did not constrict my casting.
Its hard to say how comfortable it is till I've worn it a few dozen times, but it seems to be light enough and out of the way enough to be OK>
I considered the suspenders then thought a bunch about how and when I fish in waders; typically at night in cool to cold weather where I have at least 1 layer of cloths on top of the waders. I quiestioned to myself what good inflatable suspenders are when worn beneath a jacket or sweatshirt and opted for the floataion harness which can go on top of everything else.