Tom, I never used the ROS mode live. It would need two separate amp rigs for max. effect and that is not very practical for me to carry around. The ROS mode sounds best in overdriven tones where the neck pickup is set to a clean tone and the bridge pickup is overdriven. In order to achieve that to an extent, I use the TC Electronic Vintage Bass Distortion which has the wet/dry mix feature. The 20% Heavy Fuzz / 80% clean setting sits very nicely in the mix without getting muddy in the low end.
On recording sessions, though, I almost always preferred to use it stereo. I used to EQ the bridge pickup channel, cutting the low end below approx. 200Hz to simulate the bridge pickup capacitor. It always sounded great in recordings. Anyway, that 4003 is not with me anymore. I currently use a v63 and it does not have the ROS feature




