IMHO if this is your thinking, you don't need a POD HD.
Of course - working as cover-band - I want to copy the sound of the original, hence I need a tool that gives all the possibilities to me.
Otherwise I would look for great clean sound, a distortion pedal and a good multi-effect processor.
BTW the POD HD (500) has a lot of option to get equal volumes in your sounds, i. e. the amps himself, the mixer, compressor, equalizer and first of all your experience and a strategy.
Once you've covered the unequal volumes, you aim your new sounds always to the lowest patch. That's it!
That is my thinking in a live setup. I find that cycling through amp model after amp model doesn't give me very good results. But again, I am not doing cover songs where I am attempting to copy someones tone.
As far as not needing a Pod, you may be right, In as far as I don't need an fx pedal that goes from a warm bluesy Bassman to a screaming ball crushing Treadplate for the music I play live. It's either one or the other. Rarely both on one gig. My patches are tad bit more involved than mentioned in my above post, I did abbreviate in the interest of time, but they do generally revolve around a Gibtone and a Blackface.
Lastly, you mentioned that I would be better off looking for a good clean sound, a distortion and a good multi Fx pedal. Well, the Pod is a good multiFx pedal that has several great distortions, my DT50 2x12 has a great clean tone and my Two Rock Jet rounds out the middle.
Now for recording, I am all over the map with my Pod. I use it all! Treadplate for my Fender Rhodes, Soldanos for my Didgeridoo, the list goes on and on. But even in a controlled setting like recording, I STILL don't cycle through 12 different amp models in the middle of a song or passage. At least I have yet to find that the need to do that. I am open to it if it sounds good!