when I first heard of factorissimo, I was pretty furious. I mean, infinite space within one 6x6 building? that's too much, man.

But recently I wanted to try out mods for the first time, so I started a playthrough with long reach, tank wagon, advanced drills, and factorissimo (i figured i would just turn it off if i didnt like it). I'm about 8 hours into that map, and I gotta say factorissimo really isn't as game-breaking as I figured, and it has it's own challenges and limitations that closely mirror those of the vanilla game: * the buildings are quite expensive, 500 stone bricks and 100 steel. So you have to at least get small factory going outside, even research steel outside, before you can go placing them down and rebuilding everything inside. * the buildings only have 12 input/output slots, so throughput is limited by that as well as the power transfer rate. * Also those slots are evenly spaced around three walls. So, you could build a 6 blue belt furnace inside one building, but you still have to figure a way to get 6 belts in and 6 belts out without making too many soggy noodles. something even slightly more complicated, like green circuits, requires much much more planning optimization of belt placement (one of the core concepts of the vanilla game). * you may consider fitting a 6 belt furnace into a 6x6 space to be "cheating" but keep in mind that the main obstacles to having such a furnace are actually things like: controlling enough resource patches and having enough miners to saturate 6 belts, having enough power to run those miners and furnaces, getting the plastic to make electric furnaces or supplying coal for standard furnaces, perhaps automating production of furnaces/inserters/belts, yada yada yada.

I will admit that it can reduce the size of your base tremendously, which makes defending it a breeze. but I, personally, have never thought of that as an interesting or rewarding challenge. early game, the aliens are a threat that requires you to divert a little time into throwing down turrets. Late game they become a trivial nuisance that greatly slows railroad construction, gives you constant alerts, and requires you to simply SPAM walls and turrets around everything you build. I don't understand why people act so macho about the subject... in another comment, you scoffed at the 5 RPS base because "on top of it all" that guy played on peaceful mode, like, you don't think he's capable of automating wall+turret production... or, if he were a real man, he'd have spent hours walking through biter nests with a flamethrower, building blueprinted self-repairing walls just to tear down and relocate them, all while listening to the grating BEEP BEEP BEEP constantly reminding him that ~57 turrets are currently active? thats not fun, thats just grinding, and the whole purpose of the game is to avoid that.