I have finally come to grips with the installation of my SV - GPS - 250. So many views on this and what it came down to for me was:
1/ Wanted the antennae out of airstream to eliminate drag.
2/ Full functionality with good view of sky
3/ Although hidden I didnt like the idea of a shelf in the engine compartment dues to heat and the need to bring more wires into the cockpit.
The placement in the photos required making a bracket and some nut plates in behind but in the end it will satisfy all the above concerns I think.
I am a little concerned about heat through the plexi, but many i have read here store them on the glareshield with no problems. Here in Canada it will likely not get that hot but I will have it under a canopy cover anyway. As for the timesin Arizona I think a cardboard covered with tinfoil should work.
Open to any comments, I offer this to the VAF archives for those searching, it is only my answer to a build prob and certainly is not intended for anything but information.