I voted no only for the fact that we already have Monster. I loved Ultimate. Unleashed was a bitter-sweet arrival, toting new mods, but lacking a few of the ones I grew to love in Ultimate. Monster seems to have gone further from Ultimate than Unleashed, but they are both successors.
As time moves forward, the "Mega packs" will move forward with it. I feel like adding another "Ultimate" pack would be a slap in the face to the new mods that Monster brought to the table. Each succession has been one step further in evolution and as a modded minecraft player, I want to continue evolving with it. As more mods come to the scene, I want to experience them in the current "mega pack" of the times, in this case, Monster.
If anything, I wish Monster had gone further in bringing more of the lesser known mods into the mainstream. Through forum discussion and general experimenting/searching, I've found a lot of them to be great fun. I want more people to experience them as well.