Part of the "trick" (if that's the right word) in getting the best results, presumably, will be to choose an existing amp block that is the most similar to the reference amp. Based on what criteria, though? If someone wanted to try to amp match a boutique amp that is sort of like an old Fender Tremolux, for example, would they choose the Bassguy amp block and hope for the best? Keep experimenting with different amp blocks until the user is happy with the results?