Hm if the hovernet model is supposed to be the same size as the old one (2x2 in the battlescape) it would certainly need some elevation devices (be they propellors, turbines or helium balloons
[1]) that take up quite a bit of space/volume to keep it afloat.
There are some propellor and turbine-driven drone concepts pictured in this
google-search.
EDIT: I think when Winter wrote he likes the first mdoel better he just referred to this problem, not the overall shape. At least i think he does
Other than that i really like both of the models (and the ones in
your other thread as well). Keep up the good work
Werner
[1] On the other hand the aliens could have e.g. developed a (more efficient and compact) successor to the ion drive engine as they are already in use in some sattelites and interstellar crafts by NASA. Dunno how this would fit in with the rest of the story.