For starters the headset one is more than likely a simple
analog input whereas the flightcell is fully microprocessor controlled -
has
built in intercom - satelite input/output - individual gain control on
all
channels - interferance rejection etc.


Which gives you exactly what in added functionality with regard to the
OP's
request, namely using a cell phone in flight?

Not a lot - which is why it's probably an overkill product for what he
wants - which is why I suggested the entry-level alternative
"flightcell2go".