MacBook Pro > Dragonfly 1.2 > HD-700 ... I can turn the volume to full for kicks, but never leave it there for more than about 10 or 20 seconds. I usually just use the rough volume control driven by function keys, and keep it between 4-6 notches below full volume. I also use a Focusrite Scarlett 18i20 home studio interface and a Peachtree Nova 125 when watching movies on my TV, but both are noticeably less performant than the Dragonfly. I do think I would enjoy a stronger amp, especially if that came with a tad bit of bass slam and warmth across the board thrown in, but not enough to open up my wallet anytime soon, especially since my two other main cans at the moment are the ATH-ESW9 and M-100, and I feel that both of them are absolutely perfect match with the Dragonfly IMHO. Yes, the HD-700 undoubtedly scales better, but will still show you the goods. I will admit that if Audio Technica ever made the ESW9 sound in a physical form like the B&O H6, I think it would be the perfect headphone for me as I really dig the sound of that can but it takes so long to get used to the fit and even then it is hard to keep on after 30-40 minutes....but I digress.
Not sure when, but right now I am thinking of eventually building a Crack/Speedball with my son, running the Dragonfly into that for a while, and then eventually doing something like an Oppo HA-1 or a Geek Pulse if they end up turning out real nice, or some other really good all in one, and then keep the Crack hooked up to that as an option just for the HD-700 and use the Dragonfly just as a portable alternative.