Should I Stay or Should I Go?

Honestly I have never heard such bogus in my life.
Serato is lightyears better than Traktor when it comes to beatgrid and beatmatching. The flexible beatgrid will detect variations in beat in older music, like 70s disco etc. and correct it automatically.
Even with point breaks you cannot solve this in Traktor, the beatgrid in Traktor with those kind of songs is totally wrong in any of those tracks.

Serato or Traktor is user preference and to some degree workflow decision only. None is better than the other.

Serato has:
– Beatgrid flex (what you need)
– iZotope effects
– effect chains
– Flip Remix
– Slicer
…
Serato is more geared to live performance and “adhoc” remixing.

Traktor has remix decks and stem support, however to operate this tracks need loads of prep work. Hence Traktor caters more to exact music (modern techno etc.) and users that like to prepare remixes rather than doing them live.

As far as professional DJs go, Traktor and Serato share very equal marketshare, with Serato gaining more and more since Traktor is closing off its ecosystem very rapidly.
Of course new entry Rekordbox is gaining popularity aswell, but is very very similar to Serato.

So use what you feel comfy with and do never listen to idiots.

Regardless of the software you use, on average only 80% of your tracks will be able to be beat-gridded so that it can use sync and such. That and the fact that you may want to use tracks stored on other media than in your DJ software make it very good practice to learn how to manually beat-match. That said, if you use a lot of floating beat tracks and you want to use sync for all the obvious reasons as much as possible, then it pays to use software that can handle that kind of tracks the best.