There is no debate. Those papers are nonsense and written by people who have never put an antenna into a real product. No integration details are in there.
THe complexity of the Hilbert antenna is significantly less than the other challenges faced in producing a mobile phone today. So no, it is not complexity.
Thanks for outstanding effort Pete. In course of my work I need to design quad-band gsm and gps antenna for an embedded m2m application, and I've found a number of recent academic work on Hilbert / fr ...