Yeast are probably the single biggest mystery in brewing to me, so I can just go on my experience, which says:
-Direct pitching a dry packet with no aeration will yield a good fermentation with complete expected attenuation 100% of the time
-Liquid yeast does work much faster and often better with good aeration, but is more finicky across the board
So now I only aerate when using liquid yeast. I use pure oxygen from the disposable home depot bottles for 1-2 minutes. Pull stone out, pour in decanted starter, and close it up.
Overall I find liquid yeast to be:
-More expensive for the pack
-More of a pain to handle (have to make a starter days in advance, oxygenate)
-More liquid vessels, more liquid transfers, etc, is going to increase opportunity for infection. Along this line the O2 stone in particular is highly porous and dunked in sugar water (wort) and therefore I boil it every time, just too be sure... it's always struck me as a potential infection magnet
So, I find myself using dry yeast more and more, almost any time it's an option now, because it does what I expect it to do every time and is just much less of a PITA overall.