My experience is that the insulated water bottles do stay cool a little longer than regular, which means the water is OK after 90 minutes if it started as mostly ice + cold water.
Some of the guys in my bike club do the white sock thing with good results.
I put my insulated bottles into neoprene can coozies to help keep them in the cages while insulating them against the hot metal bottle cages and heat reflected from the road.
The bottle on the downtube stays cooler longer than does the bottle on the seat tube.
A small frozen bottle in the center pocket of a bike jersey stays cool and feels great on a hot day.
For longer rides on hot days, I get the best results from a camelbak. I stuff it with ice, then fill with cold water. It will stay cold for many hours and keeps the sun off my back as well as cooling any sweat that forms under it.