As someone who has tried both and still does civil perhaps I can answer Hook Hacker.
In my field rotary I would say that military is more difficult and demanding. This is because military is so varied while civil - in my case N Sea is routine by design and nature. The oil companies don't want their pax placed in dangerous situations.
The only time that civil becomes demanding is when the weather is poor but it still is far easier than creeping up a cloudy mountainside to rescue an injured climber.
The other thing I have noticed is the wild variation in ability of civil co-pilots - some are excellent, the majority as you would expect are average but some are never going to progress to command. This didn't happen in the military as the below average never made it to the LHS (rotary). This is because during upturns, causing shortages, the companies will not be as selective as during downturns when they can pick and choose.
AP