Some initial impressions of the Roxannes vs the non freq phase JH13s:
They do not seem darker to me. Some parts of the treble spectrum are louder on the 13s. Others are louder on the Roxannes. Over all, I'd guess the Roxannes have more prominent treble. But it's hard to say without measurements, or at least some frequency sweeps. I've always felt there was a smoothness to the 13s that I'm pleased the Roxannes don't seem to have. Shrill sounds in the recording are presented as shrill.
Thanks to freq phase, I expected the imaging to be noticeably improved from the 13s. This is definitely the case. The whole soundstage is more articulate. I'd be curious to compare them to the HD800s in this regard, just to hear how they stack up to the champ.
I'm also happy to say that the Roxannes are a step up in regards to over all detail retrieval. I experienced the old audiophile cliche about hearing things in a recording for the first time. I was surprised to hear components of sounds in some of my own mixes that are completely invisible on the 13s. The space between sounds is also noticeably more pronounced.
Unfortunately, I haven't heard any of the the other freq phase offerings from JH Audio, or the 3A. So I can't say what portion of the benefits I'm hearing are just do to better phase alignment.
I'm interested to compare the bass to that of the LCD2s in the coming days. I have thus far done all my listening with the bass turned down. I'm hoping it'll be fun to adjust when listening to the occasional bass anemic recording though.