I don't believe smaller reflectors are the best solution for the future of the HP. They are just easier to handle for the manufacturers and great as shoulder tanner.
For other application "regular" rounded glass reflectors driven by 400/500 watt lamps. These reflectors are similar to the alluminium one, but able to reflect more than 100% plus of the oldest one. Is more difficult for a manufacturer to handle the cooling aspect of this lamps (see 1000 watt lamps 500 watt driven on entropy bed), but this is the best you can have on a HP unit.
Another advantage is the lamp change cost. The rounded "classic" reflector you pay just 19 $ (approx) plug in lamp.
See a 500 watt driven lamps what can do (A+B reading at 20 cm):
