They're China bikes that will fall apart before they're a year old. You'd be better off spending about the same amount of money on a Honda CBR 150 or a little more on a 250. The higher tech Honda water cooled engine would probably give equal performance even though they're smaller and last much longer. Also, good luck getting parts for them.
First the Honda CBR150, CBR250 or even the CBR300R are complete other motorcycles, not only in riding style but also in riding behavior The small Honda CBR’s are unmistakable sportsbikes, while the Stallions Centaur CT400 is a classic retro style motorcycle.
Sure the quality of the Honda engines are very good, but nothing wrong with the low-revving 400cc single-cylinder engine of the Stallions Centaur 400. The Stallion engine was originally designed by Honda as a 500cc, which was reduced to 400cc and the fueling was changed to a modern electronic fuel injection. The EFI and the ECU is from Delphi, which is an American company.