I have to say that on single pickup basses, like the P, the volume control probably (stress probably) isn't as critical. But on basses with more than one pickup, where the likelyhood of actually mixing the pickups in varying amounts is high, then volume pots that have a more linear curve are very helpful.
I modified my own VMJ to have independent outputs (one for each pickup). I began to use a modular synth signal mixer for mixing the pickups after I did the 2-channel mod to the bass. Using the synth mixer, I immediately noticed FAR better control over the pickup mix after I did the mod and used something other than the stock Squier volume pots for dealing with pickup mixing. I can only imagine that using better quality pots would have something close to the same results. I have no personal experience with the "CTS" pots, but if they are even a little better than what was installed on the bass from the factory it has to be an improvement.
I did, however, change the pots to Alpha 250k pots (some I had kicking around for amplifiers) and that seemed to be an improvement over the stock ~stuffs~. It's like the operational curve of the stock ones is far too logarithmic, meaning ~nothing~ seems to happen until the last 20% of the sweep is used, at which point there is a large change making the volume controls very touchy.
On a side note, I'm glad that I did the 2 channel mods for many reasons, but I never thought that getting a better pickup mix with greater ease would be one of them.