Both my Song and B6 tickets were about $86 each. Also, because of work, I was not able to make the original dates of the trip. B6 waived the change fee almost without me asking, and DL charged it (though maybe they did me a favor not chargina an add collect, the check in agent was very nice).
I also looked in to a short notice BOS to MCO trip. Fare on B6 about $175 roundtrip, Song wanted at least $335, so I booked B6.
I do like the idea at least in the short term of flying with Song to get the 2 for 1 tickets. Also Song sells food where as B6 only has the free snacks. However, all B6's planes have the tv setup, where as only a handful on Song. If Song had priced out (not in T class) for $150-$200 I would have probably bought the ticket from them due to the 2 for 1 deal. However, I'm not going to pay hundreds of dollars more for Song, and this way I'll have tv service for sure. Also B6 has free same day standby, where as Song has $25 same day confirmed. Song has some interesting cocktails like a Song Sunrise, and I have not yet checked out B6's cocktails...but I will

. So they both have some things going for them.