Here's a demo for a "progressive death metal" piece:
I am a raging Amorphis fanboy but I've never tried to actually record a death-metal-type piece before. (Classic hard-rock/stoner rock/proto-metal is more my comfort zone!) I took a different approach in AmpliTube, also.
Rhythm guitars are quad tracked. There are two "wider" tracks that use the VHandcraft 4 for a more contemporary metal tone, and then two slightly "wide but closer to the center" tracks that are mostly the Metal Distortion 2 (of course!) through a clean amp (the SJ50, I think, though I am not sure it matters much!). The lead guitar uses the Orange Rockerverb 50 (with the SSTE delay stomp before the amp). I don't usually use IRs much, but, for this, I decided to take advantage of AT5's IR-loader to use 3rd-party IRs from a Swedish producer well-known for his work with metal bands. There are different IRs for the two types of rhythm-guitar tracks ("normal" and "chainsaw" ) and for the lead guitar.
The bass signal is largely split between clean (and aggressively smashed!) low-end and distorted high-end. For the distortion, I used the MiniPlex 20, though again run into the AmpliTube IR-loader with a 3rd-party IR from a Finnish-based (of course!) maker of metal-oriented IRs, plugins, and suchlike.
There is a fair amount of post-processing on both guitars and bass (and everything else!); by no means am I exclusively using IKM plugins, though some T-RackS EQs and compressors are in there. As usual for me, T-RackS Stealth Limiter is the last thing on the stereo bus.
Keyboards and synth choirs are all done with Logic Pro's synths and Sampler; drums are done with Logic Pro's "Drummer" feature, plus some hand-programming of certain parts and the use of some third-party samples.
The lyrics are all in Old Norse, basically cribbed from the medieval poem "Vǫluspá". I did my best to give them a reconstructed medieval (instead of Modern Icelandic) pronunciation. I am sure actual medieval Scandinavians would find my accent laughable but, luckily, there are not too many of them around! The verse lyrics are all performed in "Cookie Monster" style anyway.