There are 2 benefits to using a 3 conductor IEC cable instead
- Better grip thanks to the ground pin in the IEC socket
- Some grounded power cables are also shielded, but most are not.
Of course, you only get benefit #1 if your IEC socket has a ground. For this reason I upgraded my Luxman’s socket. The ground is not internally connected but it increases the grip strength by about a third.
I also use shielded power cables to reduce the chance of picking up noise from all the networking and streaming gear I have behind the rack.