I didn't ever turn it on with the dome intact so I can not tell you. I used the heat from the re-flow soldering to assist in the proper removal of the dome. I did de-dome my original XM-L emitter in the light and it was around double the CD. This one is so bright though, it seams like it is putting out more light than it originally did even before any modification, without the dome. I also got a couple other lights and put one of the new XP-G2 de-domed leds in them and they really throw for their size. I looked into doing what Saabluster did with his new MB and it was a large pain in the butt, because if they are not perfectly focused they do not put out much light at all. I got a C8 body and did the same process with it and the throw was amazing when I got it perfectly focused, but otherwise not all that great. There is a lot of work that goes into these modified lights, so when you consider the new online price of a TN-31 XM-L2 version and the price of the TN-31MB you almost have to go with the MB. I would love to see what Michael could do with an XM-L2 in the TN-31 body that was over driven as much as the XP-G2 is in the MB. I think it would be too awesome and wouldn't be allowed to be sold. It would probable put out close to 1900lm OTF.