I am running a DX-7 (2.4) in my extra- so far so good..... I have had low voltage re-boot issues in the past, (not with this plane) so I am not taking chances anymore... I run unregulated A123's (2ea) 2300Mah ea. without issue. Also, after about 3 to 5 flights, I only put back MAYBE 500Mah into each pack. A123's are also cool for me because I can quick charge them at the field or any event I go to whereas if t were something else (NiMh or NiCd) it would take considerably longer. These packs can be charged at up to 10A. I charge mine @ 7.5A. Takes only a few minutes to put the juice back. you will need to buy a specific charger (A123 only) but I think it's a pretty good setup.
Back to the 2.4 stuff- I have the AR7000 rx, and it is PACKED! but works well. the only change to "box stock", was the addition of a 24" remote rx extension.I built a lite ply box to raise the rx up to about an inch below the canopy, and mounted the remote where the "pilots" headrest would be. (right behind the canopy in the turtledeck) obviously perpendicular to one another..... I'll attach some pics in a bit- the ones I have on my computer don't make sense as they are at an incomplete stage of completion... Hopefully they will make sense..