don't change anything to the airplane design....... it's a great flier !!!
fully aerobatic and extremely stable.
mine is performing fine since the maiden flight. no gear troubles, no fuel feeding problems (either with the relocated tank), no problems at all.........
rudder speedbrakes are efficient

look this landing......

http://perso.wanadoo.fr/rcu-stuff/landing%20dv.avi



and this pass with gear down
I found the droopy "vortex style" wingtipps giving him a impressive "bomber look" on that pic, LOL


a friend of me (the valuable member strykaas) will post a video on this thread showing a take off of my DV who nearly turned very bad !!
the only problem with my retract setup is that the prop clearance with a 14 inch prop is critical.
Now I am flying with a 13/7 3 blades, but on the vid it's a 14/7 ............
the prop touch the ground and the plane take off with a heavy roll mouvement induced.....
fortunatly you will see a 91 fx is a great puller and the elevons are very efficient either in the critical phases of flight

you could shorten the engine box a bit less than I did, this could allow you to put a longer leg in the front. my DV balance without lead with the shortened engine box and the retract setup .