1.

this would be part of a larger trip, so i have about 2 nights i could dedicate to hanoi/halong bay or amanoi. we will be exploring the rest of vietnam and some of laos for more nights on the trip as well, but the amanoi vs. halong are the two places i have been waffling between filling the extra time with. i feel there are mixed reviews of both.

2.

is there any benefit to doing a private boat vs one with other people? both of the boats you guys linked to seem nice, nicer than the private ones i have seen with 1-2 cabins. normally i would rather be on a boat alone not with other people and also then have the benefit of dictating where we go and when, like if we want to skip an activity or stay longer at one.