Turbosquid is the major seller, if you choose to exit Turbosquid guild membership you should diversify and upload your models not only in CGTrader but also in other websites.
In my opinion CGTrader has the most modern interface and sellers have much more freedoms than in any other website. Im looking forward to its growth so thats why i choose to diversify and not to give my work to TS alone.
If you choose this path i recommend you to have a website/blog, Facebook page, Instagram, Pinterest, Tweeter, etc. to promote your models and send traffic to CGTrader.
Thats my plan anyway!