Sets and trips are similar in that they both make 3 of a kind, but they're not the same type of hand.
of hitting a set is 8.3:1
-If you hit a set, you are he only player in the hand that can have that set.
-Sets on paired boards always improve to a full house.
-Sets usually win your large pots as the chance of getting set vs set is very rare and your opponent will have to make a better hand than a set to win. Also, sets can very well hidden. So, you might stack someone with AA if you have a set on a dry board.
-Odds of flopping trips is 73:1
-If you flop trips, you may not be the only player with trips.
-Trips can cost you a lot of money if they don't improve. Have 78 on a board of of 2884A can be very dangerous if your opponent has an 8 with a better kicker like 89, A8, or a set of 2s or 4s.
-Trips aren't hidden, so you probably won't stack a player with AA if they don't improve.
Also, when discussing strategy or talking about a hand, using the correct terminology is crucial as story or discussion might not make a lot of sense if you're saying it's one thing but it's acutally another.
So, saying you had a set and you lost on a board of 553K7 to an opponent holding A5 won't make a lot of sense to me because if you had a set, you should have one. If you meant you had 56 for trips and lost, that's completely different.