The powerSun is a good MVB bulb, but not as good as the ReptileUV's bulb. I would still use D3 just in case a few times a week, im pretty sure that they cannot over dose on it. Id rather be safe than sorry. (This comes from owning many dragons while using D3 and MVB bulbs, someone else may say different)
This is thing about Beardies, every single piece of advice has someone saying something different about it, it gets really confusing.