Bias:
There are a number of "ingredients" found in what sounds like sonic accuracy from headphones. One of those components, as you know, is frequency response, or, better stated, what sounds like accurately reproduced frequency response. Another one is articulation, or, better stated as what sounds like accurately reproduced articulation. Both of these "ingredients", among others, are probably equally important.
While the K701 is not my favorite headphone for studio productions, I can say that it is certainly used in studios. I would rate the K701 as a very good sounding headphone for the purpose of studio production. The sound of the K701 would probably not satisfy many audiophiles because of it's (what might be described as) somewhat "dry", "reserved", and "no frills" sound. For my tastes, the K701's sound is a little too "reserved", especially in the lower frequencies especially when one considers the concept of listening for what sounds like sonic accuracy. None the less, as previously mentioned, the K 701 is used in studios. Mixing, for the most part, however, is still done utilizing monitors.