MH for Veg. HPS for flower. HPS for both. MH for both. Dual Spectrum for both. Dual Spectrum for flowering... yata .... yata....
They all work well. All these arguments are about good, better, best. Ignore them all. An HPS lamp will grow dope. I once got a pound from my 600W HPS veg & flower. That would be about 4oz from your 150W lamp. It's not always that good but I can bank on getting 8oz. HID lamps make dope. If you want to improve your setup add more wattage. Some CFLs might be a cheap way to go.
A word of caution: HPS is HPS but Metal Halide comes in different spectra/spectrums and the ones they sell for lighting are not good for growing. You need 6500K color temp. Like wise with CFL.