Depending on brand these seem to produce 375 to 450 lumens, which is about the same as, well, a 40-watt incandescent light bulb. Two of them are the same brightness as a 60-watt bulb, so it's like you have a 60-watt bulb between each mirror. Probably enough light, especially since you have a few other ceiling lights across the room. I've seen a bathroom with an over-the-vanity lamp that takes four of the G9 bulbs, each in their own glass canopy, and it's adequately bright if not more.

Thanks! Yea my idea is to not have it so bright that I need a dimmer.