bunkers - do You build them?

[Zonk]

I've had SP games where Marr and Miriam both have softened up a City before landing the Marines. But as stated above, the AI makes poor use of attack waves. I've had Sven use Marines a lot, also, but don't recall any Air Power used in conjunction.

[Sikander]

Thanks for all of the replies. It sounds like bunkers are of limited use to me, as they will overlay certain terraforming improvements, don't help against airpower, and the AI is seemingly powerless to mount a decent invasion.

I have been trying to perfect my "hollow" empire strategy, whereby I place my bases 2-3 squares apart along the coastline of my continent. Even placed 2 squares apart, this leaves me enough land to get them all up to 16 pop, with only a very few bases needing supplemental nutrients trucked in from the interior. My terraforming scheme is pretty simple. First, if I can put a borehole in a square, I do. If a square is rocky, it gets a mine. If it is not rocky, it gets a condensor / farm. All shelf squares within the production radius get kelp / harnesses. I only work boreholes and shelf squares, every other square gets a crawler. Most bases work 5 or less squares (with workers that is) which really keeps drone problems to a minimum. The 10+ engineers that each base has by the early second century really powers my economy.

For defense, every coastline square is occupied fairly early with either a Base, a crawler, or an armored probe team. Thus I am safe from invasion until marines, and effectively safe until much later (airpower, missles and planet busters) in single player. The extraordinary concentration of bases and units does increase the potential damage of planetbusters, but I do tend to grab a good tech lead, throw up some ODPs, and have a good deal of overlap with my flechette defenses. My 'hinterland' interior is quite safe, and I exploit it depending on my needs for nutrients, minerals or energy.

I have yet to try this strategy with anyone other than the University. I expect that it would work well with any high science faction, but I would tend to use more workers with Morgan to reap all of that windfall energy. I don't have all of the kinks worked out yet, and still have many things that I haven't tried, but I have run away with the game quite regularly with this method, in part because the easy defense allows me to concentrate on constantly improving my economy.

[Viriato]

Vel,
I have to agree with you on that; and in particular situations like defending a bottleneck I'd sure use a bunker.
The fact is that in my PBEM games (I don't play SP anymore) I always find something else I need my formers to do. Also in the games I've been in the most usual attacks were with rovers, marines or choppers/needlejets and were aimed at the bases, not the crawlers. Apart from defending against the 'rover rush' the bunkers are useless.
However if I have a land border with another faction it can be a good idea to have strategical placed crawlers to create ZOC's that can prevent a land assault while gathering resources. In this particular case I'd say that building bunkers in the crawlers positions would be a good decision.
Again this would probably make your enemies change their approach like using 'nerve gas' do destroy your bases.