People should read, and study in detail, the official Foma curves - they're pretty good and they've been published to guide, and not to confuse or deceive, end users.
Foma 200 achieves - easily - 160EI in a range of developers. If ultimate 'effective speed' is a concern, I'd recommend people try it in Xtol 1:1, or the recommended (excellent) Xtol clone made by Foma, Excel, or, even better, Fomadon LQN.
Having said that, it's a shame that every time the name 'Foma' gets mentioned the discussion has to quickly fizzle out (sadly, due to a few members who have never once posted a breakdown of their methods, tools and a sample of their results) towards the dumb 'real box speed or not' discussion.
Plenty of us get excellent shadow detail with Foma using the recommended developers, interpolating the data from the leaflet, aiming for standard target gamma values (.55-.62 depending on final usage for me) and measuring
correctly using well
calibrated meters (I trust my Sekonic Studio Deluxe 398A III) and - most importantly - using them consistently in a wide range of light settings.
For those lurkers out there contemplating whether to invest or not into understanding Foma's consumables (100, 200, 400, retropan, ortho) do it without hesitation. Their stuff will reward testing and it will not represent the bottleneck in your workflow (apart from Foma 200 in 120 which has had for many people serious batch-dependent issues with soft emulsion and scratches).