Incandesant bulbs output apx 17-19 Lpw, lumen per watt. Flourescent
screw in bulbs apx 50-70 lpw. Tube flourescent 60-110 Lpw, or 4-6
times the output of what you have. Actualy incandesants are heaters that
output 90% of their energy as heat and only 10% as light. Using a screw
in Cfl will up efficiency apx 4x, using tube T8 can up it 6 times. But a
recesed fixture will still loose you 50% of light output.

I will guess an exposed fixture of T8, electronic ballast of one 30
watt tube could equal those 2-150 watt bulbs you have, quite a savings
and it will last 5x longer. You can also run dimmers on certain
electronic ballasts for real control . Go to an electric supply store
for real info, but converting to T-8 electronic ballast, exposed fixture
is the way to go for light output and power savings.