I have no particular use for a FLGR. I've used them, and can do fine without them -- i. e., with the old fashion short rod and solid plug. I do use a tungsten FLGR in my competition gun, but I've really noticed no real difference in performance with or without one.
This is, however, one of the perennial and irreconcilable debates in the pistol world. No one, AFAIK, has come up with any "scientific" proof one way or another.
adapt, improvise, overcome
"Extraordinary claims require extraordinary evidence.", Carl Sagan
"One should shoot as quickly as one can -- but no quicker.", Jeff Cooper