We have driven on both in the past 12 years including T/T and we both prefer the automatic chains. They are expensive and they are a convenience to us with a lot of side benefits.
We have the OnSpot chain system:
Onspot Chain and you can read about them there. The chains are most often seen on school buses, ambulances and fire trucks. The telling thing for me is the school buses in the mountains use automatic chains.
Why we like them:
Not having to pull into the dangerous chain up and remove chain areas
deploying the chains in icy rest areas, customers locations, and icy truck stops
Not waking the person sleeping to help install or remove the chains
Not having the wet muddy clothing brought into the truck from working outside to get the chains on or off
the ability to quickly remove the chains when we are not on ice or snow to save on the wear and tear of our tires
As for the weight.... We have wide base singles and the weight of carrying those chains is no more than the weight of the Onspot chains.
When the snow is deep it is time to find a place to pull over and wait the snow removal equipment from the safety of a non moving vehicle.
Last year I put on a few 100 miles driving at 25 mph top speed with the chains and they performed flawlessly. We took the chains off during summer and are now putting them back on for winter and hoping we do not have to deploy them.... They are an insurance policy as a way to keep our truck and ourselves safe.
DD that is a great idea to practice putting chains on in the summer as in the winter with snow blowing is not the best place to learn.