About the SAI vs SEI model, I'd also choose the Good Iron / Navy as I prefer function over looks.
Appearance - SAI
Recoil - About the same, according to various posters
Muzzle rise - SEI
SAI follows the size of the flash hider more closely, giving better looks. SEI also makes a NM version of its Navy brake that follows the flash hider size, but I couldn't find it in Canada. No import either. Too bad as this was my first choice; function AND looks!
The SEI model has 9-12-3 o'clock holes and angled top ports.
The SAI model has 9-12-3-6 o'clock holes.