A simulator is a nice safe world, where you can stop at any time....
In the real world, you would be worried, scared close to panic and more importantly very very stressed.
As I said I would go for the automatics, why do PPL and ms sim pilots think they know better than ATPL crew?
The senario would be something like this, Both pilots are incapacitated, if your lucky you will be in the climb, not the cruise. So you get one of them out of the flight deck, sit down, do you know how to set the seat set up?
So you strap in and in and look at the instruments, are you climbing, are you straight and level what's your speed? flaps, are they up, is the gear down...
Okay deep breath, time to talk to someone, where's the ptt switch? Press the wrong one you end up with a siren, how do you engage the autopilot, if your holding the yoke why won't it engage?
Assuming you make it this far, remember you are on your own at this moment...
You get hold of ATC, which country are you in, do they understand what you are gabbing on about?
Lets say you decide to return to your departure airfield, how do you turn around. what switches do you press and when? what if you get it wrong.....
Lets take it you can get the height and speed off, even to the point of Flaps and Gear Down, 1500 feet agl with a autopilot engaged. Is this the point you disconnect?
A 737 feels a hell of a lot different than a 172, its controls are heaver for a start.
You see your high on the glide, you push the nose down, now your 1 dot low speed too much, do you take power off? if so how much, 2 or 3%, which gauge to look at? now your speed is low, how do you get it back.
If you don't disconnect,engage the 2nd autopilot as long as the raidos are tuned and you have pressed the VOR/LOC and APP (737 Classic) you have a chance.
Anything else is Russian Roulette, you are not only risking your life, but potentially the lives of hundreds of others as well. Nothing kills faster than cockiness.