I had both at the same time..
Use the GL on board system.. I had Autocom gear in my helmet. the big online GL store has adapters to make them talk. The I put an Autocom system on my FJR (For sale BTW it is a PRO 7) Then I could use the Autocom on both.
I did not care for the JM setup. I did not like cutting my helmets for speaker installation. That is why I changed..
The Autocom is MUCH better at noise rejection on the Mic
You have choices.... For a wired system, I agree with the above. You can listen to music too but you'll find the Autocom speakers not so great for that (but not awful). Edsets speakers better, but mikes are crap.
However, I'm now wireless with Scala Rider Q2's. Mikes are perfect. Pair them together for intercom communications, or get a buddy to buy one and talk bike to bike (and your passenger too). But, be aware bluetooth is still a flawed technology. Music will be tinny due to small speakers (worse than Autocom) and is mono. There are other bluetooth headsets out there that are stereo, but they are way more expensive.