FlyerTalk Evangelist
Join Date: Nov 2000
Location: Atlanta, GA, USA
Programs: Frontier Gold, DL estranged 1MMer, Spirit VIP, CO/NW/UA/AA once gold/plat/comped gold now dust.
Posts: 38,138
Don't forget that Spirit considers bags "overweight" at 40 pounds, not the industry standard of 50. It's not hard to get to 40, especially if the bag itself has some weight. There's also the disparity in carry-on policy to iron out, and Spirit also has a few flights like the LIM ones where they won't let you even pay for an additional bag (i.e. embargoes).
You could argue than an A319 beats a jungle jet, especially if you have a carry on you can carry with the A319 rather than having force-checked.