have not owned BAT or VTL, but have owned some ARC and SF L3SE in the past. SF L3SE, despite its large power supply, does not offer as much bass weight as other reference class pre amp though the quality of bass is top notch.
if what you are after is tight and deep bass, check out Einstein pre amp. another pre amp to consider is EAR top model with transformer coupled output stage.
if what you are after is tight and deep bass, check out Einstein pre amp. another pre amp to consider is EAR top model with transformer coupled output stage.