I agree the faceted helmet gives less visual distortions. But, just as you say it also limits viewing area. A Spacesuit is basically a design by compromise. The ideal can't be reached and even low pressure suits are a pain to use for such simple things as touching your feet with our hands. When Apollo Astronauts knelt the volume in their suits changed forcing their helmet up where they could no longer see the ground!

The CCPS was a high pressure suit. I've never see a comparison for it with the nude range. But, I'm pretty sure it was not as good as the contemporary I-Suit or D-Suit...either just might be okay for Mars use...they're still heavy when you add the PLSS and are as like the EMU a prebreathing lower pressure suits. They still use some roller bearings (a dust issue on Mars), but have soft torsos and nearly match the nude range in some flexures.

BTW, foot placement is key to walking over rough terrain and in Spacesuits seeing your feet is key to not falling. A properly designed hemispherical faceplate allows better viewing of your feet. That is better than most other designs.

--Chris Vancil