Acoustically, what makes the difference in sound between different models of whistle or recorder is bore and windway design, not the fingering system or the material they're made of. Susato make "Renaissance recorders" which are the same as their whistles but with the fingerholes in different places - I use their G alto and G sopranino a lot for Scottish music. These are parallel bore with a curved windway, which gives a lot of power in the lower register but crappy response at the top end (notes up there are hard to start and flat). This design was abandoned by recorder makers some time in the Middle Ages. Upmarket whistles tend to use reverse conical bore like Renaissance or Baroque recorders, which improves intonation in the upper octave. The more expensive they get, the more like recorders they are.

I'm regularly asked what the green plastic recorder in the photos on my website is. People just don't expect Scottish session tunes to emerge from a basic primary-school recorder - my repertoire and the way I play it makes them think it must be something else entirely.