The problem with amps is that they're not necessarily made to sound good at whisper bedroom levels. They're designed for the stage and live sound reproduction. This is where the POD wins. I can come extremely close to a true amp sound. Sure the POD sounds a little sterile since it's not a real amp, but I personally feel that is a minor deal compared to the overall nice Marshall or Soldano tone I can get.
If I lived in this building myself where I could crank an amp then maybe I would, but I don't think you can beat the POD for applications where you want not to be overheard.
I don´t think so... Unlike in the 70´s, most modern amps sound good at bedroom levels. I mean, you don´t have to crank them to get the best of them. Most all-valve amps nowadays, get their gain from the PREAMP stage, not from the POWER AMP stage.
I also play mostly at bedroom levels nowadays, so I know what you´re talking about. After years of tone-search, I can tell you that you can´t have 10-20 amps in one. Modellers like the POD try to emulate the character of famous amps, and sincerelly, that´s quite not a laudable objective... at least to me. I think you have to find your personal sound. Maybe a couple or 3 or 4 different kinds of sounds, but I don´t see the point of having emulated several amps, and many stomboxes, just to have an infinite variation of tones. Perhaps I´m old-school, but I think it this way. It´s not for nothing that most professional musicians use some stompoxes, maybe a couple of effects racks, and the amps of their choice. They don´t use PODs. Most of them.
I think you can get some good tones with the POD, but at the end of the day, they sound artificial. Perhaps if you never owned analog stompboxes and all-valve amps you aren´t able to compare, so you keep what you have and you are happy with it. What I observed, in my experience with digital modellers, POD HD 500 included, is that you can dial good finished tones, specially if you don´t use an amp and have FRFRs, for example. With finished tones I mean tones that sound as a finished track. But if you´re talking about wooly-raw-coming from a guitar amplifier-tones, that´s where modellers fail.
Anyway, that´s just my 2 cents.