It is pretty inevitable. The louder you get, because there is a cutoff, the more information you lose. This loudness is not so much a "loudness" thing, but it is a process of finding the most appropriate amplitude to cutoff without having any detectable loss. Thats where the "distortion" comes in. it is not a distortion that you can hear, it is a clipping - a loss of information. Have you heard Immortal's At the heart of Winter?...It is a pretty loud record, but records from the Abyss studio seem to be able to be mastered higher, but that one in particular clips like a motherf**ker. Compare it to Follow the Reaper by COB, you'll know what I mean. I think it does depend on the qualtiy of the equipment you are using, but it also depends on the particular patches you are using etc, but more importantly, how loud is loud enough?
On puritanical the guitar tone is very smooth, it has had me debating its extremity for a while now. All the drums are short and snappy - so they cut through the mix without being particularly loud, (I think that is the nicest snare on any p-BM reocrd, imo.). It is the combination of these things that allows a record to be mastered higher...Puritanical is a good example, because it is mastered very loudly, it almost gets annoying with the amount of guitar clip you can hear in places. Have you heard the devil's path re-recording? it is so loud that it completely fucks the clean intro up!!!! down with overly-loud mastering I say.