I was to pull the trigger on the HD500, hmmm good tiing, i guess. Let's see what this thing can do first.
Im' sure it gots lot of FIZZ ? you should explore the DEC more and i have no comments at this time moment. OT..You see Digital aliasing or Impluse response were inpeded on modelling that is why digital aliasing D/A were still not perfect that's all I can say for the moment
But if you can afford an AxeFX like Radley too you dont need DEC or Harmonic Converger. See his review on AxeFx but still he uses the Harmonic Converger just to make his sound more purist and not need not to overdubb his tone in studio recording by his technician and no sizzling annoying fizz even in high gain territoty. Cliff of AxeFX is a former sonar engineer and a musician long before time, and he is a software developer doing reverb as IR impulse Response. Later as a musician also he venture to MODELLING inpulse response doing reverb meaning if you feed a convention musical tone or voice to it to, it will convert his algoritmic instruction so the injected feed sound or voice would sound like HALL, CAVE, and such and later he venture to develop AXEfx modelling several Preamp AMP like Mesa Boogie Mashall, Soldano, Peavey Fender such and such. I think Cliff is a genius and perfected his Impulse Response for all type of Preamp out there eg (JCM, Vox, Marshall etc) He perfected and pioneering digital modelling at its best. No doubt even many great artist replace their analog set up and using AxEfx NO need for analog setup coz AxeFX truly cupture the modeller without Fizz or digital aliasing.
My advice is if you can afford an AxeFx ultra is great but same as me I can't
I'm very much got my solution using Harmonic Converger or DEC. You can ask porksisig even his Digitech RP1000 using with DEC was totally enchance and clean out the annoy Fizz and sound pure like ANALOG thing.
No further comment, lets wait for GT100 im not sure