1. I prefer the value and convenience of the 6-quart smart change box and the recycling opportunities it provides.
2. I dislike the color green that Quakerstate uses on their bottles. I find it garish and unpleasant.
Otherwise they are both high quality synthetic motor oils from well known and established companies, and I believe the meet the same or similar enough specs. Your engine won't know the difference and that leaves completely trivial points like which brand/logo/color you prefer.
have you looket at Autozone. Rotells gas truck (works in cars too) for $2/qt on clearance. There is a rebate for $2/qt as well so the oil would be free after rebate.
With price and product being equal, I would get both and see which works better for your application. If there's no difference, you have two go to oils.