Tactical nukes and Conquistadors.
The7Sins said:
Even taking into account any ICBMs shot down my SDI (assuming I let the AI get that far) it is still more cost effective to spam them than tac-nukes...
Really? For each hit with a tactical nuke post SDI you can expect to pay 400

(cost/chance to hit=250/0.625), and for each hit with an ICBM you can expect 2000

(500/0.25), how the heck is the meagre cost of subs going to eclipse
that gap?
They aren't even more cost effective before SDI, as a tactical nuke + sub costs just 400

vs an ICBMs 500

, and thats the worst case scenario for tacticals as each sub can carry 3 (total 900

for sub + 3 tac nukes vs total 1500

for 3 ICBMs)! I think that level of hammer saving is, contrary to your post,
far from 'minimal'. And this is ignoring the fact you can launch tacticals from a city belonging to you or any civ you have OB with,, or your own forts, so if you can hit them from there you won't need as many subs....
On time taken to move them, nuke wars are most effective when using units to take cities after the nuking, and if you have to transport land units then theres no extra time wasted. Also, remember that as ICBMs cst twice as much they take twice as long to build.
Besides, you can move the subs before even building the nukes, as provided you have OB you can teleport your tacticals to your targets cities and load your subs there.
Range may be an issue on large/huge maps, but on standard I fid it rare that I can't use subs and nukes to hit every city, and with paras, wipe out a civ in a single turn. Even on maps where you can't hit everything by capturing/razing all their coast and near coast cities you should be able to cap them in one turn. Besides theres nothing stopping yo topping up a tactical nuke force with a few ICBMs if you really need to hit something.