In general, Vizio TVs have great picture quality for their price. They are not as well polished as the main brands offering, but they offer one of the best value for the money that you can get.
Vizio has a relatively simple TV lineup, but it got more complex in the last few months with the introduction of the D and R series. The Vizio TVs are separated into 5 main series, with a wide range of sizes for each of them. There are some differences between sizes inside each series, so it is more complex than it looks, especially across years.