I think all saws will make accurate cuts if they are set up properly and they will stay that way. The biggest differences in saws is the size of the work area, horsepower, how accurate and stable the fence is, and whether the miter gauge is tight in its track. Of all of those the fence is the most important. Incra sells a miter track bar that is adjustable so the loose slot can be fixed with it. I don't know those saws so you might try googling those models and add the word "reviews". Sometimes you can find quite a bit that way.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.