Serato is great because you can visually see your tracks side by side. This is helpful to me because I line things up with my eyes and ears.
Traktor is different in that you have to be more reliant on accurate beat grids and syncing (at least first), but the software (to me) is more sophisticated and more difficult to learn. I’ve just started to dive into Traktor and it is amazing. If I had to do it all over again, I would probably have went in that direction.
But ultimately it’s about the music not the software.