You can't compare like that. You have to take into account the human eyes and the "ppi" of that. There is only so much the human eye can differentiate.

One thing we can agree upon:
RGB > PenTile
AMOLED > LCD
16M > 16K

The absolute threshold of the human eye is 300 ppi. In real life it is lower though because you hold the screen at a distance, less than perfect vision, sun glare etc.

The N9 has 3.9 inch screen 480 by 854 pixel pentile
ppi is 251.2

Sub pixel ppi is 355,2 (pentile)
equivalent RGB is 435,1 ppi

Obviously RGB is better, but both sub pixel resolutions are way beyond what can be detected by the eye. The true ppi is still only 251.2 for RGB because it needs a triplet to reconstruct each pixel. The pentile has only 2/3 of the sub pixels, and R and B sub pixels have lower resolution than the RGB. Still, due to sub pixel rendering, the same true 251.2 ppi is also valid for the pentile. The only exception is fully saturated red because then the sub pixel ppi will become less than 251.2 even, approximately 1/3 less.

I don't see pentile as a problem at all for the N9. The problem occurs when the sub pixel resolution gets lower than 300 ppi, because then you start to see each sub pixel. That thresh hold is much lower for pentile than for RGB.

The 808 has 360 by 640 RGB 8 inch.
ppi = 184, ppi_pentile=260, ppi_rgb=318
With a ppi of 184 is starts to get pixelated, but you still cannot differentiate each individual sub pixel. All in all, it's not perfect, but adequate. But a pentile on the 808 would appear much more pixellated because you could then start to differentiate each sub pixel.

The L900 has a true ppi of 217 and a sub pixel ppi of 376 (RGB). It appears more pixellated than the N9 because the true ppi is lower and under 300 while the sub pixel ppi is higher than 300 on both.

The SGS3 has a perfect screen with 306 true ppi, even when pentile. It is impossible for the human eye to differentiate each pixel. RGB wouldn't help a bit.