it's very hard to answer without knowing a little more about anyone's spending patterns.

just as an example, the hilton amex offers 5 points per dollar for gas purchases. So if you use a lot of gas but don't fly alot, it can offer advantages (though some people point out that discount cards may offer more)

United has several different cards that cost up to $140 a year, and the most expensive gives you more United points and extra eqms for United tickets, and 5,000 eqms for taking the card, but is only advantageous if you buy a lot of united tickets or need the 5,000 points to get status.

in addition, many people use the airline cards to reach a certain point level to get a trip to europe or wherever, so where you are on points now and where you want to go, can also affect what the right choice should be.

all that makes it hard to advise without a lot more information

but i think the summary in the thread you reference is still pretty accurate