If you want a "long lasting string", you want one that's a bit too bright to start with - strings lose a bit of their initial brightness quickly, and then the change slows down a lot - they are pretty stable for a much longer period. So, if you like a string right away ("that's just right"), unless you have a tech to change your strings daily, and an endorsement deal where you get strings for free, you have the wrong strings - you need brighter ones, because you want them to sound good when they're stable, not out of the pack.
I've used the same strings on different instruments, and had vastly different impressions of their life spans. Why? On a bass that has brighter pickups, the combination is too bright to start with, but after a bit of break in, they sound great for a long time - their stable sound works well with that bass.
On a bass that's less bright, the strings sound great out of the pack, but a couple weeks later, they're "dead". It isn't the string's fault (my chemistry isn't making one set of strings die quicker, they're the same strings), I just need to start with strings that are a bit too bright on whatever bass I'm stringing up.