"what sort of situations would you use the output (mic position) of the 302"

Some cameras, like the XL2, don't have line inputs, although I use attenuators in that situation so I'm at least running a line level to the camera (it's safer). Some wireless transmitters, like the AT1800 series, will only take a mic level input as well. Also, some cameras have non-standard line inputs so it's easier to match the impedance with mic level, but that's kind of rare.

Which mixer is best SD 302 or SQN 4SIIIa??!?!?!?!?!
 

The 302, has input and output limiters, 2 stage gain, upto +20dbu meter, tone and slate, 2 XLR out, VU/Dbu meter is color coded for line and peak, but shows the entire headroom too
Is roughly about 5 years old.


The SQN has 1 channel extra, only one stage gain but attenuator from -10, -20, no input limiters but 40:1 output limiters, 2xlr output and 10pin hirose, could be upto 15 years old
PPM meter means you mix to broadcast standards, but does not register the headroom after. It doesnt have a slate mic.

They both have the same panning and hi pass options.

Tough call opinions welcomed!!!!!

Lee