I use traktor too, absolutely nothing wrong with it compared to serato , traktor seems to be aimed more at producers djing where as serato is aimed at Djs who don't produce. Also traktor is a lot more sensitive to minor turntable issues than vinyl is as vinyl will ignore minor fault errors where as traktor picks them up and starts skipping. First thing mate download and try dpclat and run it while your mixing. It will tell you if your pc is struggling to keep up with the latency anything apart from a green bar chart means your laptop is struggling performance wise. Traktor is a lot more sensitive to needles as I said above. I actually narrowed down an issue where when I had 2 cables coming out the sound card too close together it was making the tracks skip(if I stopped the vinyl on the deck I could see it wasn't detecting silence on the graph it was producing some noise and leading to minor skipping)took me days to narrow down the issue . Moving them further apart resolved he issue . ( try to avoid a spaghetti junction of wires and route them around neatly)
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Also just to add, the guy i bought my 1210s off had re wired the headshells with the wrong wires. It actually worked perfectly with vinyl, I called him up and he was like oh yea actually now you mention it I think i wired them wrong cos a cable come off and i just stick it back in a random place it seemed to work ok, after a bit of butchery I fixed it but I still need new shells at some point... worked with vinyl but with traktor it was fked. (vdj actually dealt with it as you could inverse and specify setting more accurately, but anyway what i'm saying is if your vinyls work fine It doesnt mean there is nothing wrong with your turntables as traktor is more sensitive to issues.
Side note personally I think Traktor is more advanced as a tool then Serato, serato has just gained market share for simplicity for djs as DVS, much more advanced stuff in traktor for producers, Although I don't use it to its full capacity I switch the BPM counters off etc from the menu. Only got it cos it was cheaper.