Never had it, but I did work with a guy once who seemed to never get enough of it. He raved about Swiss Chard.
Is it a salad ingredient? As most leafy salads don't freeze well unless it blanches well, like spinach does. You could try freezing it.
I suppose I could try to grow it one year, if I ever see the seeds available. I usually like to try a different thing every year. Just to see how it does, and if I like it.