What you are hearing is what many HD users have been complaining about. I noticed it after a couple of months of using my pod HD. I like to call what you are hearing 'digital artifacts'. You only hear them when you are pushing an amp into overdrive or using an overdrive/distortion pedal. It's really annoying and very obvious. I know that some line6 people are claiming that it has been intentionally built in to mimic the amps but this is beyond amp modeling because it happens on every amp or any time you put an overdrive pedal in front of it. I was hoping that it was something they would fix with a firmware update but it doesn't look like that will happen.
I've owned every generation of the pod, besides the very first one. I practice with a pod x3 and it doesn't have any of the fizz, digital distortion, digital artifacts that the Pod HD has. I do think the amp modeling is better and more with the HD but I'm to the point where I'd rather play through my x3 because the 'digital artifacts' are annoying. If you use in-ears or headphones it really is noticeable. And if you have a good PA you can hear it.
My co-worker has an Axe-Fx which is far superior to any of the line6 products and it doesn't have any of what I'm hearing. I've A/B the pod HD with the Axe-Fx using a Vox amp. Axe-Fx has no fizz or digital artifacts. You can hear when it starts to break up but that's different than what the podHD is doing . Again what's annoying is that the Pod X3 doesn't have it. Unfortunately i've told people to stick with their older pods because it's too annoying. And if you can't hear it I seriously question your ability to hear.
I've even tried using my pod x3 for just the amp tone and running my pod HD as my effects and pedals, bypassing the amp. And as soon as you turn on the overdrive pedal the 'digital artifacts' are there.
So it's pretty disappointing because I think the sounds and features are great but the 'digital artifacts' are bad enough that I'm going to have to start saving up for an Axe-Fx or go to a tube amp and pedal board. There's no way you should be recording with a Pod HD if you want a quality recording.
