I have been able listen to the 3 cap values in the output (2.2, 3.3, 4.7). Like it's been said- the 3.3 that are included in the kit really hit a good mark for clarity and bottom end. In my room with my speakers which are a Fostex Fe206en in a large back loaded horn (diy Vulcan design) the 3.3 does sound the best of the three overall. However, I do like the extra bottom with the 4.7. It comes at the expense of a touch of realness, tone, clarity, and distortion compared to the 3.3.
If I do a cap upgrade (jupiter ht flat stacked or mundorf sgo) in 4.7uf value it will still have the same filtering but the voice is what will change? In other words I think 2.2 vs 3.3 vs 4.7 I just need to be happy with the filtering for my system related to the frequency. Then decide on particular cap manufacturer to imprint the voice (realness,tone,distortion,pace, whatever else) of the cap. I like Chris Cornell's voice. We might sing the same note but I'm pretty sure his would sound a ton better because we were made by different people.
Eric