I've been lurking on here for years but this is my first post. Last week I was about to solder together a 2nd pair of v6's as a backup when I decided to check the Symphone web site and saw there was a v7. I stopped with the v6, ordered the v7 and finished putting it together last night. I emailed Rhydon and he still recommended using the 3D printed beta cups with the v7. All solid silver cabling and silver plated plug along with 10 hours of pink noise burn in.
The v7 is a definite improvement over the v6. The mid bass bump has been smoothed out and the bass is tighter. One thing I noticed with orchestral music and other highly layered music was greater separation between instruments. Overall the sound is crisper and more precise. Definitely much better than the v6 for classical and music with real instruments. I did listen to the headphones before burn in and noticed that there wasn't a huge difference after initial burn in. This is very different compared to my experience with the v6 which had overwhelming loose bass initially before settling in. And the v5 which I found to be lacking in bass and only became acceptable after a burn in period. So you could say the v7 is actually the best of both worlds from v5 and v6.
I'll be keeping my existing v6's for the time being alongside the v7's. The v6 is better for bass heads, electronic music, dance, etc. It's not as articulate as the v7 but it's still fun. I do have an extra pair of brand new v6 drivers now if anybody is interested.