I break a lot of "rules" with my strings of choice. And I do it for several reasons. I actually began using lights exclusively in order to help maintain the geometry of my Guild guitars. As time went on, I began to appreciate how pliable lights were. I play fingerstyle and fingerstyle only, and lights are easier to manipulate in my opinion, without wearing my bare fingers out. I began to prefer them.
Having said that, there's another alleged "rule" that I now break. Some say in order to "excite" an Adirondack top, you've got to really hammer it, then it gets loud. : ) Well I not only run lights on my adi topped Collings, I use Silk and Steel strings. I can't imagine a louder guitar, even set up like that. Oh, there may be louder guitars, but it's plenty loud for me. There have been several players better than I am play my D2HA set up in that fashion, and all of them seem to be blown away by the amazing tone and volume.
Now I could be wrong, but it would seem to me that if one spends a few thousand dollars on a guitar, they may set that sucker up anyway they like........but that's just me. : ) String choices, action of the guitar. playing methods and styles, body type, wood varieties, pick thickness, microphones, pickups........these are all factors that make our playing unique.
West