So as a lot of people have mentioned, defensive structures seem very strong, and many think they need a nerf. But I think a portion of this issue comes down to the map layouts. Im not sure why stardock went with this current method. Maybe they are trying to mimic Starcraft??(which specifically has air transports, units that can quickly move around the cliffs or has areas that can be destroyed to open up new lanes of attack, besides the fact that SC defenses are incredibly weak)
But what we end up with in ahes is that most maps consist of very clear lanes. And we all know a lane is much easier to defend than an open area. I can cram all my shields/AA/guns into the same little area, and i can block the entire region behind it. Some maps are so linear there is literally only 3 lanes to attack? Is this DOTA? Many of the 1v1 maps have 1 choke point that controls not only access to the enemy base, but acess to resources, so who ever has the most defenses on that choke first, usually wins (PHC wins here hands down with arty)
Even in sins one could fly around what ever defenses were posted at a star well, so one had to put in measures to stop people from flying around the defenses or they had to cover their well with weapons.
I think if the maps had more channels to attack an enemy from then that enemy would be forced to spread out their defenses, which would inherently reduce the effectiveness per cost of the defenses.