The idea behind the wingnuts is great bit I can’t recommend them based on durability.
well I have a wingnut and yeah the zips are starting to go and a bit of the “wall” between the bladder and main pack has ripped away from the stitching at the top, however the thing is over 6 years old and I’ve used it a lot, I’d get another, I guess I’ll have to in the next year or two.
But to answer the OP yeah I was getting some backache while using a camelbak, swapped to wingnut and no more issues, they also have belt pockets easier to get to, more stable and hte pack doesn’t it you on the back of the helmet when you go down really steep stuff.