I don't know enough to compare to the Seidio cases, but my wife loves her Ballistic case on her iPhone, and I just ordered one for my nexus. If you decide to go that route, ___ found a Cupon code for 30% off with free shipping
the difference between SG and SG maxx is that the maxx adds a screen protector and a holster.
Current: Nexus 5
Previous: SGS2 Skyrocket, SGS Captivate, HTC/AT&T Tilt 8925, HTC/AT&T 8125