I want to start off by saying I think the technology that allows 32 bit float to operate in a portable recorder is amazing.
That being said, to me the benefits for the actual recording are dubious and this point has been made numerous times in this thread.
Let's start with these facts.
1. The maximum dynamic range of the best analog signal capture/amplification equipment made generally stops at 120db.
2. Rock concerts have maximum sound pressures coming from the stage/PA between 90db to 110db on average, depending on the venue.
3. Typical concert crowd ambiance averages 40db (for between songs babble and shuffling around, not cheering/roaring applause)
4. The dynamic range potential of the 24bit PCM format is 144db.
So, if you were to record a rock concert soundcheck in an otherwise pin drop quiet empty room the dynamic range could theoretically reach 120db.
If using a 24 bit A/D with levels peaking at -12db, the analog noise floor will be down 120db below that point, or -132db, with 2 bits to spare.
When the audience comes in and fills up the seats, the effective dynamic range of the music falls to 80db, since the crowd chatter and racket becomes the new noise floor at -40db.
Since -60db to -50db is the lowest level mark on the meters of most recorders, even a recording that only occasionally lights up the -40db mark and is gain boosted in post will still retain 104db of dynamic range.
Bottom line, with the same analog signal source it's not possible for a recording in 32bit float to exceed the practical dynamic range of a 24 bit recording, even with levels barely hitting -12db on the meters.
So, what's the big draw of 32 bit float in a field recorder? I see it as primarily to benefit foley, ENG, and nature recording challenges. If I was recording a frog sitting on a rock in a stream croaking, and BOOM, a crack of thunder happens, I'd feel far more confident setting levels with 32 bit float recorder than 24 bit recorder.
For concert recording, I just don't see 32 bit float being essential or substantive to proper level setting.
With all that said, if I was in the market for a 2 channel recorder I could use right out-of-the-box, the F3 is at the top of my list, but not because it's format is 32 bit float.