The amount of excitement here (both positive and negative) seems undue, considering that this unit will appear so late in the game that you (hardcore guys) won't see it in 99% of your games.
In my case, almost all war happens during that last few percent. So having endgame units be sci-fi will make the game feel sci-fi. And if I wanted that I'd play a sci-fi game. Maybe I'll play V differently, but as it is war happens at 3 points of the game, 2 of them optional:
1-- did I start with someone else on my island? If so, rush. the "war" doesn't last long. If not, build peacefully.
2-- I discover cannons first. DIE LONGBOWMEN, EAT HOT BALLS OF LEAD, AHAHAHAHAHAHAAHA. This war is against my nearest enemy, maybe nearest 2 if both are weak and small. It lasts a bit longer, but it's still a fairly small diversion from my builder habits.
3-- Endgame is approaching, I have a SOD with plenty of artillary, modern armor, and mech infantry, all begrudgingly built to prevent the AI from declaring war so I could concentrate on building as much as I could. It now occurs to me that I may as well do something with them, and I have them devour the rest of the globe like locusts.
This third stage is long, seemingly dragging on for, well, longer than I'd care for it to, honestly. The empire building part of the game has fallen away and I am now playing a war game. This is a big part of the game. And again, if I'm doing that with giant death robots instead of tanks, it's going to feel very much like a generic scifi game and not at all like a civ game =/
So yeah, once someone makes the simple mod to replace that with something that isn't a joke, I'm gonna be all over it.