One fish isn't necessarily better than the other but comes done to your preference. Swai fish and tilapia are very similar in taste, texture, and price, and can be used in place of each other in many recipes. They are both farmed fish, and while tilapia can be found fresh or frozen, swai is shipped from Vietnam and is only found frozen in America. Tilapia is also fattier than swai with dark spots in the flesh.