We all want a fast plane. But with autorotation, the faster we go, the larger the disk AoA. This is due to the faster the plane flies, the higher the speed difference between the advancing and retreating blades. The way to solve this is to increase rotor rpm and this is usually done with tilting the mask back which increases the AoA of the rotor disk, and that counters directly to the increase of traveling speed. So, at present, the top speed of an gyroplane is about 100mph give or take a few I am afraid.