Right now this feels kinda too overpowered, since it's literally better than normal bots. They're extremely cheap (x45 is way too much for a single repair pack and two pieces of coal) and are way faster than normal bots, even with the first few speed upgrade researches unlocked.

Making them slower (reduce speed by 0.75?) and slightly more expensive (x10 for a repair pack + 10 green chips + 10 iron gears?) should be good enough for rebalancing I think. I'd also remove the additional space for another roboport in the heavy armour, it's pretty unnecessary and only makes the balancing worse.