adding second coil: increase power handling and Bl, lower Fs?

A while back I ordered a custom recone kit going from a single 2 to a dual 2 coil, and I was wondering if there would be any noteable increase in power handling, Mms, and efficiency as well as a lowering in Fs since there will be double the coil... but I think i was mostly told not enough to be note worthy.

Later on I painted the cone, and suddenly I was being told I would totally mess up the drivers SQ and SPL by adding mass and making the cone stiffer (obviousely mostly by noobs and tards)

Anyway, Exodus Audio's GEN II Maelstrom-X came out. Basically the only change was going from a single 4 to a dual 2 coil. The added coil length was enough that they changed the power rating and Bl rating.

http://www.hometheatershack.com/forums/exodus-audio/19584-maelstrom-18-gen-ii-landed.html