OS numbers have been updated with actuals. Looks like the weekday estimates were way off: It made over 19.5M on Monday-Thursday, and it was estimated to be under 17.5M.
$28,073,848 OS this weekend, more than Doctor Strange (26.4M) made on it's 4th OS weekend. However, DS was hit hard this weekend OS by Fantastic Beasts. On its 5th weekend, DS made 8.94M (Not counting new markets). It will be interesting to see if GotG2 can match that with PotC opening this week in pretty much all OS markets. If it does, and GotG2 has the same legs DS did, it would end with 465M OS.
It definitely has a chance to match DS's 8.94M next weekend, but it will get hit hard again the weekend after, when it ends its run in China, and Wonder Woman comes out in nearly all markets. On the other hand, a bigger percentage of DS's gross came from China, which shortened its OS legs. So there's a decent chance GotG2 could still match DS's OS numbers and end with 465M OS, despite the heavy competition in the next 2 weekends.
I'm still going with 380M domestic, so that would make for a total of 845M WW. If it manages slightly better legs either OS or domestically it may still reach 850M WW. It all depends on how well it deals with PotC and Wonder Woman.