Regarding safety: I'm of the mind that this truck will rollover regardless of one's configuration, and my driving reflects that.
As for comfort on the highway: I did not notice any improvement disconnected. I drove mine disconnected a while before lifting (disconnected front and back). Then lifted the truck and connected them, then finally disconnected again. Like many others stated, the real comfort is experienced when off road. When one tire drops down, the sway bars will yank the vehicle around side to side. First to the side you dropped down in, then abruptly to the other side.
Although this point gets heated debate: I've filmed myself going through the same obstacle with the same approach, both connected and disconnected, and know for a fact I am getting better articulation when fully disconnected. I don't know if you're asking about all this or just the highway driving aspect.
If you're lifted, and disconnect both front and rear on the road trip, you might have a kiddo vomit in the backseat. Hard to notice from the driver's seat, but the ride gets a little wishy washy back there. Especially on country roads.