It depends what you are looking for. There is nothing better than plastic lense for deep diving, because the plastic gives the mask more flexibility and compressibility. So, in this point of view, there is barely some mask that can beat the Sommap Flow or Aquasphere Sphera. They are also excellent for UW rugby.
If you need a low volume mask with large field of vision and a flat lense, then I just discovered yesterday the
Beuchat Maxlux. I am a fan of Technisub Micromask, because of its excellent field of vision, but I was completely blown away with the Maxlux. Low volume (137 ml), but such a field ov vision that you practically don't see the mask skirt or frame at all (well, the mask has no frame in fact). In the same time, the mask is very comfortable, no painfull pressing against the eyebrow, nose, or teeth, and it seals perfectly (at least we got a very good seal on three quite different faces).