Without getting too technical.. with 32bit-float recording the real-world dynamic range of the recording is determined by either the limits of the microphones or the the analog input stage of the recorder, whichever is less. Although neither of those exceed the ~144dB dynamic range of the 24bit-fixed file format*, the absence of any recording trim controls in 32bit-float mode eliminates the possibility of error in setting initial input trim.
In reality, when recording content of low or typical loudness it shields folks from worrying about recording at what would otherwise seem very low input trim settings where the the meters are barely registering. The important thing is not really the 32bit file format itself (24bits is more than enough) but a good enough analog input stage and the design of the ADC in the recorder.
Using 32bit-float will require level setting (normalization) and file format conversion afterward, but eliminates level setting in the heat of the moment, be it necessary or not.
Perhaps ironically, it actually prevents tapers from "running levels hot", as many have historically preferred for reasons good or otherwise. Using a recorder in 32-bit mode, "running hot" can only be achieved within an external preamp.
*A quick search indicates that real-world dynamic range capability of the SD Mixpre recorders is around 142db, the Zoom F series around 131db.
