I have no problem moving any of my modern machines, and could probably life them with one finger. My Singer 96K40, on the other hand, is another matter; despite it's small size, it's surprisingly heavy, and I struggle to pivot it into, or out of, it cabinet.
But that is nothing compared to the Juki DLU-450 I'm currently restoring. To move it just a couple of feet takes all my strength, and I have to lock my arms into 'fork lift truck' position before sliding them into the throat/harp of the machine.
The darn thing will give me a hernia before the summer's out.