It’s interesting and certainly worth investing in if you have a single space to defend from missiles, but it’s worth noting these are essentially a single S1 gun each, so around 300dps. You are not going to deter fighters with these unless you have 20 or more of them. The missile variants will probably be better but then you need to go restock them.
Miners, yeah. I think forget them for military bases.
With the shield and cooler left off they have zero signature due to their excellent armor, so likely they cannot be targeted by a fighter flying in with missiles until they fire. They get first shot. That’s reason to load missiles. This also makes them useful for recon. Use them for things that don’t require real fighting and they win. A couple guys with rail guns in one of these could be the perfect incursion team in many instances.