Hi!
I just bought the DDJ-SX-W and I love it! I haven't tried all the effects yet but I think they sounds really good.
There's a couple of Traktor mappings for the DDJ-SX and I've tried this one from JaJa Artwork: https://maps.djtechtools.com/mappings/1336
JaJa's Traktor mapping works really well and you can easily re-map buttons to suit your needs, but I decided to switch to Serato DJ and give it a try and so far I love it.