Networking Helix 10 si G1 with humminbird 999 si

Hey guys, I'm looking to get a helix 10 si G1 to add to my boat that already has a 999si.

A couple of questions:

1 - does the helix G1 (Not MEGA) use the same transducer as the 999?

2- if I network, what can I expect to be networkable? sonar, SI, downscan, maps, etc

3 - with the Helix 10 being the primary unit, does the quality of image decline? I have heard of this from other units networking, esp MEGA, but I'm not sure on this case

Thanks in advance!

Same transducer.
Network transducer for sonar, di and SI if wanted and Waypoints. No maps you will need serrate cards.
Not sure what your 3rd question is. Quality is the same whether they are networked or stand alone units.

Are these both mounted in same location? If one at bow and other at console, generally people use a different transducer at each location. At least for the 2d signal.

There are plenty of YouTube videos on networking humminbird units that will show you what to expect