Are you retired? Just wondering how the flexibility fits in with time available.
For us the certainty of a confirmed seat is worth the price (and often cheaper if you end up with unplanned hotel costs added on top of your staff travel ticket cost).
We have travelled right around the world on confirmed tickets booked well in advance at a good price when we did have staff travel (with one of the major Alliances -- there's a clue!) available to us, Many asked us if we were going to use staff travel and we said that we were specifically ruling that out because we didn't want to risk wasting time and money with the uncertainty. We wanted that certainty to help us enjoy the trip.