I am a UA 1-MMer, so in the past flew a good number of times (e.g., both before an after TED). But haven't flown much with them in recent years and am not clear about some of the changes that the airline, in particular WRT to MP. Am no longer much concerned with MP details, though. What I would like to understand, especially before I pull the trigger on tickets US to South Africa, is the distinctions between Basic Economy, Regular Economy, Economy Plus, and Economy Preferred. What does each of those get you?

I appreciate that economy basic, when it is offered, get you the bare minimum of a seat somewhere in the back which they will assign you at the last minute and no free checked backage. But as a lifetime Gold (until they decide to pull that back), if I buy economy basic, I save a few bucks (maybe 10-15% of regular economy), I get assigned an Economy Plus seat (maybe even Exit Row), and I can check bags. So why pay for Regular Economy unless there is no Basic Economy Preferred offered? Am I right abut this?

Now I look at tickets to South Africa and I see "Economy Preferred." That leaves me confused and the reservations agent wasn't of great help in explaining how it differs from Economy Plus. Is the seat itself any bigger or otherwise more comfortable? What does one get for the extra money?

I am thinking about business tickets for this long flight, but it's a lot more money!