Here's something I've been following for awhile and finally got one today: http://www.hifiheadphones.co.uk/forum/headphone-reviews/2821-martin-logan-mikros-90-stereo-headphone-review.html
Brillaint review and I see what you mean about similarities. The Mikros, P5, H-K BT and B&O Form 2 on ear style headphones have formed a little niche. I have heard the P5 and Form 2 and the P5 win mainly on comfort.