First, not to be wise, but you can probably get the best answer to this yourself by searching on LMA and listening to a number of samples of each. However, the busman mod on the UA-5 is most closely associated with the Oade UA-5 T+mod. These mods provide a very transparent, clear, direct, true sounding rendering of the source. The Oade W+mod is, well, warmer sounding than the other two mods with smoother and deeper lows and less accentuation on the mids and highs, but with no less detail. The biggest plus that I find in these mods is that the modded UA-5's provide a recording with significantly greater detail and clarity than the unmodded boxes. The W vs. the T part of the mod is simply preference in whether you like a warmer coloration of the source or not. Many people associate the sound of the Oade W+ mod to be similar to that of a tube amp in guitar amplifier lingo.