I`ve owned both so here`s my comparison:
Body ergonomics:
I personally prefer the more traditional look of the Spector vs the futuristic approach of the Bongo. The concave body is much more comfortable for a constant growing belly like mine.
Neck profile:
Bongo is flatter, with a D shape. Spector is rounder (C shape). I prefer the Bongo.
Weight:
Spector is quite heavy (Alder / Maple) but looks more solid. Bongo is lighter (basswood) but also gets scratched much easier.
Pickups:
IMHO, EMG pickups have a trademark sound, no matter what bass you use. They have a defined, growly, almost scooped sound that`s typical of Spector. Neodymium pickups on the Bongo have more output and are less "purist" than EMG`s.
Electronics:
I find the Tonepump 9V preamp the weak point of Spectors. They`re a bit weak IMO and boost only. OTOH, the 4band EQ of the Bongo is one of the most versatile preamps in the market.
Both are great basses, but it`s just a matter of preference. Try to play both before deciding.
Good luck