zeeoo,
Try not to lose sight that power is power, so the rotor with tip jets eats power based on the thrust, disk loading and figure of merit. The tip jet nozzles will eat more power because they create high drag in the worst spot. The power losses due to fluid flow issues in the hub manifold and the blades (assuming cold cycle) are very high, perhaps 10 to 20% of the total power (vice 3% for mechanical transmissions). Losses at the tip nozzel for hot cycle are very high as well.
These factors generall cost so much power that the hover envelope of these machines is small compared with the conventonal helos, and the fuel flow in a hover is simply eye-watering.
The way to make some hay on this is like the rotodyne, where the powered tip is used for a few minutes at each end of the journey, of course.