Holmzini:
Amp modelling works on the basis of algorithms structuring sound information into a model similar to the one analysed by the programmers and individuals that were called upon to make the modeller. Theoretically, the mathematical procedure involved is usually good, depending on the company making it, thus, a good "real amplifier" sound can be mimicked. In essence however, if the mathematical basis upon which the modeller programme is created from is good, then the amp modeller should be good.
However, if it is not, the modeller should still colour the sound enough to make it distinctively different and somewhat more appealing than the dry sound you started out with.
What I described is applicable to software and DSP based hardware broadly. If you are using a simple POD however for colouring, I think you should look for a better solution for amp modelling. Even the Pro-Pod would be a better choice.
Sincerely,
God