As far as I can see most players have, as usual, taken ANY aircraft. Mostly because they are build by Boeing or they saw a documentation in the TV about them. :>
The B707 for example is the perfect aircraft if you want to serve bigger routes over 1000nm and if you can't be online F5-ing lots of time to get some aircraft that aren't available this much.
But stick to what Daveos said - the right config is important to make them earn (good) money in DotM.