Our corporate travel arranger is given the instruction "lowest possible fare" and occasionally we do get stuck with a Tango fare. I had a last minute ticket from YQM to BIL last year; most of the ticket was Y (the only trip I've ever got to use any certificates) but the final return segment was R. Normally we do get booked in a Tango Plus fare class for trips within North America.

The amount of savings on the fares is so low it doesn't have much appeal given the relative cost of the ticket. I did select the "no bag" option for a 2 night trip to Montreal this summer; I figured I could use the $5 to buy a snack box (or a beer).