But surely you'd take into account it's rack? Or am I being really stupid?
Aside from having a physical presence and ability to plug into hardware, its all software driven, so PODFarm will sound exactly the same as a POD Pro. The end output however (pc speakers/power amp/P.A. etc.) is the only affecting consideration.
FWIW Ive never really gotten on with the dual amp thing. I can always hear the two seperate amps, rather than the blend. Perhaps its my ears or the fact I know what to listen for and an outsider might just hear one tone, I dont know.
The only good tone Ive gotten from the dual amp is the Eric Johnson/Joe Bonamassa trick of a dirty, dry Marshall tone for one and a wet as hell Fender tone for the other. Thats sweeeeet.
I used to own a Line6 Vetta II, from which the POD X3 pretty much got the dual-amp thing. It was easy getting a bad tone, but I did also get great ones :)
There's a few different approaches which I used:
1. Same amp and same settings, different cab simulations (or no cab simulation at all!).
2. Find a good basic tone with one model, then start to bring in another, one by one until you find something that compliments the tone. This is obvious for the dirty+clean thing, but same goes for the higher gain thing too.
3. Bring in the bass side from one amp and high end from another.
Or just go with a single amp model.
It's been a while since I've owned the amp so my memory might fail me on the amp models..but I remember liking the SLO 100 model. The Soldano preamp model is nice too. Überschall is quite nice when you learn how the presence-control works on that model. The Line6's own amp models have funny (or stupid 8)) names, but some of them were my favourites. 'Spinal puppet', 'Chunk chunk' and 'Purge' spring to mind.
I've pretty much forgotten my favourite amp combinations, but I remember having fun mixing the AC30-model with others, like a plexi marshall boosted with a tube screamer. Very nice old school rock tone. Or try it with the SLO 100.
The most challenging thing on the amp was the midrange. I actually purchased additional cab models from a 3rd party. Many of the Line6 cab models had radical frequency curves, that I found myself not using them. I suggest you try ditching the cab models completely and maybe (high) mids in with the post EQ instead.
My 0.02 euros.
-Zaned