Yeah, the X5 can be found on eBay even cheaper than that (I believe from MacNichol). The relative prices, from my research, are Blackbird > Emerald > CA Cargo > Voyage-Air. Being the lowest priced guitar is also factoring into my decision for the Voyage-Air.
The VA is a different beast from the others - it's a full size either OM or dreadnought style guitar with a neck that folds back on itself for travel. It's really a very intelligent design, and surprisingly, they get great reviews for sound and playability. You can see plenty more here:
http://www.voyageairguitar.com/
Thanks again for the review - interestingly, it seems the X5 is the rarest of these options. It seems to me that it should be sharing the same success that the Cargo seems to. The full scale neck is a clincher for me, and honestly, the short scale is the only reason the Cargo isn't higher on my list.