I have two buggies setup differently, one with a single battery setup and another with dual battery setup. I like the single battery setup for its simplicity and ease of operation. Balance is negligible.
Castle Neu 1520 on 6S LiPo Powered Gmaxx (Nitro Killer)
Predator with OS .21TM
Supermaxx with Mach .26
Revo with OS .18TZ
Kyosho ST-RR Conversion
Ofna CR with Tekin ESC/Motor (2)
I have owned a 3905 and a truggy and never over analyzed the difference between the single and twin packs because i just accepted they were different cars. This is my first self-modified car, now I have a choice!
Symmetry is so good in the minds eye but the practicality of a single pack I think wins.