Surely one of your team of experienced cctv specialists who do insurance approved installations would be best placed to explain this stuff to you face to face?
Just because it has a high number (In comparison to G1 G2) its not necessarily the best, fitting G3 in many cases makes the system less reliable. G3 contacts are sided and are much less forgiving when you mount them the alignment and gaps have to be much tighter.
What's the risk?