I have owned a 2555x since they were released. I love how it sounds but I have always used a boost of some kind even for a rhythm tone. I typically have a second boost for solos and a volume increase in the loop. I was talking with a friend of mine and he said that the 2555 doesn't need any kind of boost at all. He did admit that for a lead sound it would need a boost. I play mainly thrash metal like Megadeth and the amp feels a little weak without a clean boost. I just recently swapped in some new pre-amp tubes since my friend suggested I may have a weak one and that is why I needed a boost. I should also add that I normally play with the master at 5 and the lead master at 3 or 4 so It isn't super loud.