A switch rod is a spey rod in a lighter, shorter length. They so you can do a double handed spey cast or a single hand cast. Hence the name "switch"
Except they are not always shorter. In fact I see the shorter two handed being the new thing for bass, but a SWITCH can be 12 to 13' long, but they are lighter weight lines for example 4 weight to 6 weight, where spey are more 8 weight and up.
I see great advantages to them for BIG rivers, but I do see they can be problematic in a tube.
Ten footer is about max for me in a tube, but I do like the casting style of the two handed.
Plus I do believe, you can cast regular fly line on a switch whereas Spey is in grains.
Some things are better left alone, Even though, some feel they know better.