It's not hard. Just ask someone who knows wtf they're doing.
I learned about luggage from rdl (who is on HN), who often ranted about his pelican cases while working in Iraq. I have a Pelican carry-on.
I was at a hotel once when there was a convention of flight attendants, and there was a gaggle of them checking in all at once, all carrying IDENTICAL hard-sided Delsey luggage. It took me under 30 seconds to ask them the make. Now the checked luggage side is done, too.
I guess the moral of the story is to pay attention and you don't have to spend a lot of time knowing what works the best.
I buy crappy luggage and once lost some time with a friend because my luggage fell apart. But that's less time than I would've lost becoming an expert on luggage before buying any.