We use the rails, they work well. Mrs V generally has the fridge packed, so it eliminates 'falling object surprise' when opening after travel. We have the shelves spaced so the milk can be removed without bar removal.
The bars were 'double' from the factory, I separated them into two singles for the smaller shelves below.
One thing I have not seen mentioned here is the spring tension (and length) is adjustable. Merely screw the moving end in or out to change the spring tension. They came so tight that Mrs V couldnt put them in.