" With your view confined to essentually the control room. All you have to rely on is your brains, wits, your sonar, and your gut instincts. Personnally i find myself alot more attentive - closing my eyes, trying to visualize whats going on up there. Other times i even find myself on the edge of my seat because the antcipation of what might about to happen is just killing me! The desire to hit F12 to releive that is immense, but when you don't do it, and succeed, its pretty satisfying."
Couldn't say it better... this is the central interest of sub games. Using an external camera, you miss this essential part which is trying to get the best possible situational awareness without seeing anything and taking decisions according to what you think is happening.
PS : correction : " using an external camera during fights to see what is happening"... nothing wrong in having an external look at your sub when you're cruising along on the empty ocean...