Say I review things for people to read, such as on a website or blog. Is it safe to say it's legal if my intention is, say, book a flight to Phoenix with some pre-conceived intention of critiquing the flight?

I wonder because I've heard at least one story where someone got in legal trouble over reviewing a service, such as a cruise trip's policies/procedures/service/clientele on their personal website.

In general, is consent/permission needed for this?

Say I want to book a flight right now and plan to review various aspects of it -- service, clients, other passengers behaviors (if noteworthy) and prices, while also taking photos aboard the plane as well.

Would I need consent from maybe a public relations department or something?

Or is this basically legal to do (a review, in general, about a whole experience)?