Currently, the only reason we consider to keep something like the defense computer is its auto repair ability. Let's first discuss if we really want it and why we (don't) want it.
I'm in favor of auto repair:
Forcing humans to repair during ongoing attacks is something that can easily lead to a slippery slope. From my experience, the best possible defense aginst a rush or continuous attacks is leaving your base and engaging the enemy waves while they approach. Letting a group of enemies inside your base is a bad idea most of the time. While aliens don't have any other option than defending the base by combat (apart from rebuilding, which both teams can do), humans often chose to repair stuff instead, making it much harder for them to push back. This is true at any point in the match, so this would be an argument to allow some means of auto repair from the start.
Another reason for human auto repair is that it gives aliens an incentive to attack in groups as this allows a greater amount of damage in a shorter time. A single sniper or a marauder that zaps until it dies and then returns to the smoking structures will be less powerful. From our experience in the summer tournament, weakening individual attackers on both teams seems desireable.
If we want auto repair, there is a number of possibilities for it:
Giving human structures a default fixed auto repair, just like alien structures (but not necessarily as strong).
Giving human structures an auto repair with a strength related to the spare power in the area.
Giving humans a repair structure like the defense computer.
Giving humans a bot bay structure, that hosts one or more bots that leave it to repair one structure at a time. It would respawn inside the structure for free after some time when it dies.
Allowing humans to build such a bot directly for a number of build points.
My opinion:
Giving human structures a default fixed auto repair.
This is the easiest but most boring approach. It would take a chance to have another difference between the teams from us.
Giving human structures an auto repair with a strength related to the spare power in the area.
This is definitely more fun than the former approach. It has a number of pros and cons associated to it:
One advantage is that it adds an amount of tactical depth: In order to increase the repair abilities (up to a maximum), a team would need to build repeaters, which serve as a weak point, since their explosion does severe damage to players and buildables in range. This could make human building more interesting just by utilitizing the current set of structures.
One disadvantage is that forwards will generally have a low repair rate as their structures usually run at minimum power while the reactor area would have good repair abilities. I'm not sure if the latter really is a disadvantage but I certainly want forwards to be strong.
Giving humans a repair structure like the defense computer.
This certainly works and I think I favor this approach. The design principle of not having healing effects and buffs provided by structures stack (see gameplay roadmap, 2.2.1.2) should definitely apply here. The range should also be smaller than that of the defense computer, so that you 1) still want to place multiple structures to get a good repair coverage and 2) have to balance your wish for auto repair against the power limitations of an area, again introducing the decision whether you should place a repeater or not.
Giving humans a bot bay structure.
This is really nice in theory, but I think that the effort of implementation and the amount of problems related to the bot AI might not be worth the trouble just yet. If we introduce a repair structure as in the former approach, it might be wise to add a small bot bay to it, that isn't really recognizable as such as long as we don't have an actual bot coming out of it. We would prevent this from stacking by having structures be repaired by one bot at a time.
Allowing humans to build such a bot directly for a number of build points.
I find this equally fun and I guess if we do introduce the bot bay, it would be nice to allow a single bot to be built for a lower price. (We could allow constructing bots from the start of the match and unlock the bot bay later on.)