I like my FP4+ in Pyrocat HD, or PMK if there's snow or ice in the scene, or Rodinal semi stand for near box speed. I tend to rate it 60-80 in Pyrocat, 40-50 in PMK and 100 Rodinal semi-stand for rollfilm. I recently accidentally shot a few sheets of 4x5 at 400-800 handheld (sunny 16 screwup, no time to meter until afterwards) and used Microphen stock-strength developed by inspection, saved much of the shadow detail and got good mid tones and highlights, I'd be comfortable rating it at 240-320 this way if I needed the speed.
I used to like Plus-x. I like FP4+ better and even though money is very tight for me I would not use Foma etc, its a false economy for my purposes... my film is less than my gas to drive even a few miles.