I left my gas tank in the stock location. The CG doesnt really change much, or if it does it is not negatively noticable to me. The instructions from DP suggest CG at 5.75". Mine is at 6.25" from the leading edge and the hard core 3D guys have theirs at 7". At 6" the Extra is a baby, but that CG is still maybe a touch nose heavy. At 6" it is stable and will land nicely. 6.25" is not much different but you notice it is more neutral when inverted.

The best most complete review I have ever read is Bill Pryors . It's alot of different places on the web, but I found it at http://www.rcaerosport.com/articles/...0/extra330.htm

-Cheech