Reply #152: I'd like to add to your first point

[EnricoFermi]

1) Bombers (SAC) - rapid response (designed to go from cold (on the ground) to hot (in the air)) as quickly as possible in response to attack. Actual times change with each upgrade (think B-52 vintage to B-1B).

Pros (flexible platform)
Can be redirected in the air.
Relative cheap (when compared to other two members of triad)
Easily upgradeable

I see another pro as:
Russia is less likely to misinterpret it as an attack on them if we decide to hit Iran with one of these. I know they can tell trajectories, but trust me, if they saw an ICBM or a submarine launch, they would freak the hell out, possibly nuking us in the process. If a bomber launches one of these smaller missiles, which is relatively undetectable due to its ability to avoid radar, they aren't going be as likely to nuke us, and they'll first learn about it when they "see" the mushroom cloud over Iran.

Both subs and silos would immediately alert all major powers, possibly triggering MAD. A bomber could be anything, and you wouldn't necessarily know until its missile hit its target.