I don’t know about the dolonite material, but I assume that those recorders were made with injection molding, the way current plastic recorders are made (Yamaha, Aulos, etc). Nothing wrong with that; in fact they are very good. However, the Bernolin resin recorders are made the way a high-quality wooden recorder is made – from blocks of resin that are machined (lathed, drilled, etc) and then hand-adjusted (shaved holes, adjusted windway, etc.) So the technique of manufacture is completely different.
Bernolin’s wooden recorders cost about $1600, and his resin ones are made in a similar manner for a third the price. Excellent value, IMHO. So comparing the material (dolonite vs resin) is kind of missing the point, which is how they are made.