At this time, check the chip, if realtek chip avoid 1073 and 1055 and go for 1185 or higher.
All NMTs can play all formats, but if the guarantee means a written commitment that you get 100% refund if one file format wont play, take that action and PM me and I can send you a bunch that wont play
If on a budget, check out the promos and get the best deals. value for money is king.