"the company looks to have judged it just right"
Uhh no. It screwed up by about $15 per share and missed out on roughly 60% more cash which is about $10,000,000,000. I don't know how anyone can say that leaving $10B on the table is judging it even close much less just right. For the company this is a bigger cock-up than Facebook but who cares the VCs really got their buck if they sold at the 11AM bang. For everyone else, not so much and I expect it will settle down another $5-10 in the coming weeks if not days.
As I understand it an IPO is so the company can raise cash and pay back its debt to the investors, not just make a handful of people scads of money. Then again, "my car gets 40 rods to the hogshead and that's the way I likes it."