roughly 2000 lumens on left, 1200 on right.

3x xml @ 7.4v left 5x cree R2 @ 3.6v right

http://www.kaidomain.com/ProductDetails.aspx?ProductId=11462
http://www.dealextreme.com/p/5-cree-r2-5-mode-1200-lumen-white-light-drop-in-led-module-52-7mm-42mm-8-4v-max-35242

The triple cree on the left puts out noticeably more light, albeit is more floody.