Depends on the species. I've seen panthers and Veileds do amazing under powersun bulbs, especially for 36" or taller cages. A lot of my customers have a much easier time raising their baby chams (again, primarily veileds and panthers) under the mercury vapor bulb, as it's a nice hot light with lots of UVB, making it perfect for species that like to bask like those do. Montane species or more delicate species are better off with a fluorescent tube like the reptisun, which allows you to control the basking spot wattage etc much better.
I have had reptisun 5.0's for years and I recently switched to a light your reptiles t5 setup. There is absolutely no comparison. The t5 is amazing. I have an Arcadia t5 and another for plant growth. The results were very noticeable. My plants now grow like weeds and my panthers have more vibrant colors than ever. If it is possible go with light your reptiles. And the customer service is top notch. Can't go wrong IMO