jumping on the bandwagon.  
ive tried both metal halide and t5s on my tank, and for me, t5s made my sps grow mroe and used less energy.  i ran a 6 bulb setup, 324 watts total. they were notably brighter. i did run a combo about 12-13k. 
i made the switch to halides, currently running 3- 150s. 450 watts total. using pheonix 14ks now. 
but for me, i cant go back, the shimmer lines is worth it IMO. when i ran the t5s, i felt my tank was missing something.