I used two plate filters in series. First one with a coarse filter and the second with a fine filter. It worked as far as producing crystal clear beer. But man it was a PITA.
First, in order to not have my filtering session turn into a nightmare I needed relatively clear beer to begin with. Cold crashing was an absolute must. But even then sometimes the filters would clog and I'd have to pull them apart and add new filters, losing a considerable amount of beer in the process.
Ultimately I switched to using gelatin. I hesitated on the gelatin for a while because I didn't want to add gelatin to my beer. I'm definitely over that.
I picked up some clarity ferm once, sort of by mistake (asked clerk for fermcap-S, he gave me clarity ferm) and the beer I used it in was crystal clear, every bit as clear as using a plate filter.