Lungbuster,don't let this topic discourage you.It happens to be one that seems to get a lot of fellows panties in a bunch.Why someone would care what someone else spends their money on is beyond me.Unless I am giving someone the money It is none of my business how they spend it.
My personal opinion is that it is not necessary,but I do believe it helps.I have had two sets of the liners over the years and I have noticed a difference in the way deer respond to me when they are down wind.I will say now my scent control routine is so rigorous I rarely get winded with or without the liner on.