I am building my personal private cloud. I am considering using second hand dell optiplexes as worker nodes, but they only have 1 NIC and I'd need a contraption like this for my redundant network.
Then this wish came to my mind. Theoretically, such a one box solution could be faster than gigabit too.
I've used the tplink ones that they're using and they've been pretty solid. I can't say how they'd fare in a 24/7 setup though since they're not really intended for that.