I can help answer this question. Full Disclosure: I'm the CEO of Nouvoyance, the developer of PenTile technology.

Because there are fewer subpixels for a given resolution, on a given size display, there are fewer places where a pin point fabrication defect can cause a dead subpixel. This increases the yeilds of the display. Also, since there is less chances of a pin point defect that will work in the factory, at power on test, that later fail in service. So, again, the reliability should be higher. But this is all about statistics.

PenTile technology should in no way effect the speed of the liquid crystal of the display. We have done many evaluations using PenTile, and have never seen any ghosting effect caused by PenTile. In fact, in partnership with Samsung, we have made PenTile displays with high speed liquid for experimental field sequential color displays that performed quite well. If the ghosting is occuring, it is incidental, caused by some other issue.

Just because a display uses the PenTile architecture, doesn't make it responsible for everything that shows up on the screen!

 

I got a D3 shortly after they were released and I have noticed that red's seem to ghost a bit. Best way i've seen is look at the red M on the Gmail icon as you move from screen to screen. If displaygeek is correct, motorola should come out with a software update (which according to my googling, should be soon) that might fix the ghosting problem. as for dust, i haven't seen any yet.

 

I get MAAD ghosting with blacks on my Droid 3.