OK, it's not perfect perhaps but that's no problem, coz neither is my playing!
I have mine set up in "direct to studio" mode all the time and use it live plugged straight into the PA. I've tried it through a couple of guitar amps and, once I'd set the POD up right, and sorted out the amp's EQ, that sounded fine too - but it's better straight into the PA, where the amp modelling comes into its own.
So, is it really that good? I wouldn't want to be without it, that's for sure - so in my opinion, yes it is that good.
:)