Posted for JIMRHER@aol.com:

 
 Ron, Colyn, Craig,
 I have the 9900BX in my L4P and many hours of flight time with it. I
 violated some of their rules because I refused to put the top antenna on the
 outside
 (Very UnSexy). Ryan told me it wouldn't work mounted in the inside of  the
 tail on my aluminum plate, with an UPS GPS antenna and a WSI antenna. I can
 tell you that I have had traffic at 12 o'clock with holding 1000 ft below me
or
 climbing through my altitude and I could watch there distance and altitude
 on
 the TCAD coincide with there alt. hold instructions or by watching them climb
 through 0 altitude right in front of me. My bottom antenna is mounted
 between my  gear doors on the outside and it is putting out two Horizontal
lobes one
 to  each side, while the top antenna its putting out two horizontal lobes for
 and  aft. The inherent problem is that at the 45* points of the 360* you get
 the lob  interfacing and very often you see two targets at the same distance
 but  shadowed at the 45*. Ryan tells me that this is normal and you do get
use
 to it  and can easily tell the difference. I don't think it has anything to
do
 with the  antenna placement.
For the Legacy, I know you can't put it in the tail like mine and the
 wingtip doesn't sound like a good idea, so I would consider putting it on top
of
 the glareshield in the center of the windshield even if it is close to other
 
 antennas.
 Good Luck,
 
 Jim Hergert
 N6XE (An Sexy)
 L4P 350  hrs.