I got a KickPort and it definitely improved my bass drum tone. Put a good BD mic about an inch from the hole and it's an incredible, powerful sound. I don't stuff anything in my drum, use an EMAD on the batter and the KickPort itself muffles the front head a big from its weight. Both live and in the studio, I get that wonderful combination of a big, full, breathy sound and the punch and definition necessary in modern music.
I generally tune the batter side the lowest pitch that the drum shell and head resonate together and I tune the resonant side just a hair higher. Theoretically when you hit the drum hard, the pitch, due to the head stretching from impact, goes up. When you hit the drums hard the resonant and batter ring together and you get a more full tone at those higher volumes. When you hit the drum softly, the higher pitch of the reso side compliments the tone by adding depth.
Occasionally I use a ribbon mic like the CAD Trion 7000 in addition to a dedicated bass pattern mic. I put the ribbon a few inches in front of the solid part of the bass drum head to capture the boom and overtones. The ribbon mic gets a smooth and even detail, whereas bass drum dynamic mics scoop the mids and are unidirectional, great for punch. The ribbon has a figure 8 pattern which picks up ambiance behind the mic too.