I'm unquestionably with Matt...mostly becuase as it actually probably allows for more shock absorbsion and vibration than double sided!
Although shock and vibration is a complex question of frequency/intesity/inertia/momentum/other randomly chosen engineering terms that sound techncial, Velcro allows for more movement, and at this scale I'd def consider things to be more isolated with velcro than double sided.
I've not had ANY electrics fail in more than 5 years of racing...so for me that's good enough reason to think that velcro works perfectly!
I also like the quick removal, moving about'ness of velcro too
Pulling esc's/recievers off double sided is orrible! Always feels like your going to rip the thing apart before it comes off the chassis
That said, one benefit to double sided...space...velcro is thicker, so if you have limited space then double sided could possibly be a marginal benefit.