I've used QS and it seems to be a decent oil. However, i think better oils can be had for the same or less price. My unscientific rating system of the budget oils quality might put QS dino and Superflo dino about on par with each other with Havoline and TropArtic a notch above (and still cheaper in most cases than QS). I would have no problem using QS or SUperflo in my car, both are decent and do their job.
QS Semi-Synthetic/4x4 seems to be a decent oil as well and as far as value for the dollar goes, it might be a better value among the "blends" than regular QS dino is among the "dinos". Among the blends though it's still hard to find a better value than TropArtic (aka Motorcraft) if you can find it at Walmart. Walmart does carry the QS Blend in the 5 qt jug though, which is nice.
My Dads toyota dealer uses QS 5w30 Blend as their bulk oil and Dads Avalon seems to run fine on it, burn no oil, and the oil stays clean in appearance through the 5K oil change.