Downwind, what I like about the main is that it can be kicked over with the kicking strap, and will have the benefit of the boom stopping it from flogging around as the jib tends to do if the wind gets too far astern. A big jib really can flog as it fills with and spills the wind, and the rig takes shock after shock.
Often, I have to sail dead downwind, or near so, as the Great Glen...
Great Glen Way
....really is quite narrow.
If the wind is well astern, the main is better behaved, and really does not flog much, though not so easy to kill as the rollerfurl jib. You have to round up head to weather to drop the main on my ship, but you cannot have everything.
You could whisker-pole the jib, but I have found that even the largest jib I have does not pull quite so hard as the big main.