It comes down to opinion on the HUM issue.

A great deal of effort and time, and devices (noise gates ring a bell) is usually spent trying to get rid of HUM. Why anyone would actually want to add it to their tone is mind boggling.

The HUM IS what causes the ghost notes everyone on these forums has been complaining about. It's not a question of IF. The line frequency is modulating the signal going through the amplifier, and this modulation produces + and - frequency products. The ghost notes appear as these modulation products, and they are multiples of the line frequency and the fundamental frequency going through the amp from the guitar.

Your preference to have these discordant notes present in your tone is noted, but I'm certain that if 1000 guitar processor users were polled to see if they wanted these notes in their tone after it was demonstrated to them what they sound like, 99% of them would say, "no thanks, I prefer my tone without these ghost notes".

The HUM certainly was added. You can not cleanly remove something unless you added it in the first place. Sure, the amp they "modeled" may have had these ghost notes to some degree, but they didn't model that part of it. They simply added it as a modulation to the signal audio. That's why it can be adjusted in the HD.

The same goes for the transfer function characteristic (amplitude out vs. amplitude in) of all the L6 amplifier "models"; they are essentially all the same. Listen closely to all the amplifiers, except for frequency spectrum differences, they all distort essentially the same way. L6 used one or two generic distortion curves throughout all the models, and placed them in different spots within the amplifier's signal chain. The frequency response of each amp is different, and that's why each amplifier sounds slightly different.

On the other hand, if you listen to the Fender Mustang models, this is not so. Each amplifier has it's own characteristic distortion. That's why Fender has taken over a huge part of the modeled-amplifier market, and why the L6 guitar amps drastically dropped in price within the last year.

Anyway, it all comes down to what sounds good to you. What ticks me off though is the manufacturers are much too often making choices for me on critical aspects of the design, rather than giving me the option to choose. And Fender is no better in this regard.