[Noble713]

Defensive bases are only useful early in the game, and only then when you are just struggling to hold what you've got.

Early game advantages: Relatively long-ranged (due to their base mount bonus) and powerful considering their cost. Also big and hard to kill (with respectable shielding and point defense).

DUC-armed Space Stations supported by satellites make an excellent warp point defense. Missile-armed bases probably aren't as good as missile WPs for planetary defense.

Late game advantages: Um, none. If you put on enough shields to stop an enemy battle-line, you probably won't have enough room for weapons. Also, mid and late-game bases are EXPENSIVE, largely because of their weapons and defenses. By the time you can build big-@$$ battlestations and starbases, the enemy that has forced you onto the defensive probably has dreadnoughts, and even a few (say 6 or so) of them can smash the base that you've spent 2 years building.