I think the headphone versus speaker debate comes down to what your sound priorities are.
Headphones tend to have a flatter listening response because their sound isn't impacted by the room. Some listening rooms can impact the response of a speaker-based system, especially with bass, by many decibels. This causes annoying augmentation and/or complete suck-out of certain frequencies and can ruin/hamper the listening experience.
By comparison, a great speaker-based system just sounds more open with appropriate imaging. I detoured a few years with headphones and could never get the same illusion of performers occupying the listening space.
Using well-designed and implemented room treatments helps a speaker-based system sound closer to a headphone-based system in terms of response, although a world-class headphone system will always maintain the advantage.
You'll be hard-pressed to get the spaciousness of a quality speaker-based system with headphones though. That open window, 3D sound when everything is working is awesome.
It certainly takes more resources, planning, and patience to get a speaker-based system to sing correctly. Its much much easier with headphones.