They are quite different. 1st difference stems from the 300's ribbon drivers in the mid-high range. 2nd difference is that the hi section is an 3tweet array. All this indicates that all the way down to the sub, the sound is "ethereal" with a touch less "punch" than the V (which have dynamic drivers), the details in the vocals are angelic rather than meaty (V); strings are better with the 300, the highs are a question of taste between the two (I'm not sure I don't detect a lobing from the 300's 3tweets), the bass is more difficult to integrate in the 300 in a normal sized room -- there seems to be a bump b/ween 50-70 Hz whatever you do (but that's easily attributable to the room). The 300 also go lower more easily. Subjectively, I'd say the V, being a small speaker, integrates sub+upper range a tad more easily/better...
What is it about the V's you wish to improve?
What is it about the V's you wish to improve?