It's basically a matter of personal liking.
Build Quality wise Sorento is way ahead of Tiggo 8.
Power wise Sorento V6 is way ahead of Tiggo 8 (1.5T).
Look wise Tiggo 8 is ahead of Sorento.
If your buying for a short time and only want to have fun with the SUV, and are concerned about looks, then buy the Tiggo 8.
If your buying for long term and want a quality SUV, then go for Sorento.