Each of RGB "sub-pixels" you mean.
Latest non-pentile (striped RGB) AMOLED sub-pixel config is:

RGB|RGB
RGB|RGB

Whereas the N9's is:

RG|BG
RG|BG

So 50% higher sub-pixel density, spread over a wider gamut of primary colours.
Having said that, at a pixel level the N9 still has 15% higher density than the SGSII for e.g.
And by all accounts it's brightness & contrast is better...
The way the panel's mounted so close to the glass, & the CBD tech also lend a hand.
Then again, marquee phones like the SGSII also implement similar things IIRC.

jakiman's comparo with the SGSII was pretty favorable overall
http://shootspeak.com/2011/10/08/scr...ung-galaxy-s2/
Seen several other anecdotal accounts which suggest it's better overall too.
Except for in some scenarios where pentile can be more noticeable.

I'm still not 100% sure that pentile alone, explains what's going on with your screens.
One of you has an E7, & it definitely shouldn't look better overall.