I don't sell in super saturated categories, I mostly sell long tail items that show up on the first page of search if the search is sufficiently narrow. Yet I have been using PLS since the early days of PLS, because it has value for sellers like me...not on the search results page, where I don't really need it, but on the other pages (including the view item page) where my stuff can appear even though the buyer isn't actually searching for my item. Call it browsing, discovery, serendipity, whatever you want, but if PLS puts my item in front of the right buyer at the right time---a buyer who isn't searching for it, might not even know it exists---that buyer might end up buying it. In fact, I'd bet most of my PLS sales have been of that type.
Now, the thing is, since my stuff is long tail, since it is NOT bought with an eye primarily towards its sell through rate, I do not expect it to sell quickly. It will likely sell eventually. The advantage with PLS is that it might very well sell more quickly with PLS than without.
However, that extra sales velocity is only worth so much to me. And that is why I rarely choose ebay's suggested rates. Selling it sooner is nice, but for many items I'd rather wait and sell it without paying ebay an extra 15% or whatever. An extra 3%? OK. Maybe more depending on how long I've had the item, shifting buyer interest, etc, but---and this is just me, others are in different situations---generally speaking, I'm willing to wait a while, or maybe try some free methods to speed up the sale (social media, for example).
So, yes, I think it has value to me, a seller who isn't in a saturated category. But that value has definite limits.
