Interesting discussion on this topic.
I came into the modelling world via an ART SGX2000 (google it!). I went back to amps for a while but then got a Behringer V-Amp and then moved onto a POD XTL, then the X3L and now the HD500x along with a DT25 amp. And I've had a Variax 600 for quite a few years.
I got to the stage where it became simply about value for money. I liked the sound of Fender amps, but I also liked the Marshalls. And the Vox AC30. But I couldn't afford all of them. And what about pedals! I wanted a Tube Screamer, and an Echoplex, and others. Also, I was playing at a church where we were trying to reduce the on stage sound as much as possible. So the modellers became a great compromise.
When it comes to amps, there are so many variables - where are you standing, where is the microphone, what type of microphone is it, how hot are the valves etc. I love the fact that with the POD I can DI into a PA and I know the tone is good going to the desk. What the PA operator does with it is beyond my control!
I think the discussions about whether a POD will ever be exactly the same as the real thing are missing the point. It's more about convenience. I can't afford all those amps and effects (and guitars) but the POD / Variax combo gives me access to those tones. If you can afford all those amps - go for it.
And why do we assume the goal is to sound exactly like the amp? IMO the goal should be to find the right sound for the song we're playing.
Do keyboard players have the same discussions? I'm sure they'd all love to play a grand piano on stage, but they're probably very content playing a keyboard with access to a multitude of sounds that they could only dream of ten years ago.
Bottom line - find what works for you. Great tone will take a while to get from whatever gear you're using.