Is your requirement to talk to others as you will probably be solo on your LD rides, or a battery that will last all day and then change quickly? For me I find the SC1S (Sena) unit in my Schuberth lid does the job.
I have to agree with Dave - If you were concerned about getting separated and want to get in touch it would be easier to use mobile phones through helmet intercom.
I use a PackTalk bold too, appears to be reliable over last 24 months or so. If you interested in talking with riding buddies then this works great, but as described above only really useful for line-of-sight comms.
Just general communication between a small group on ride outs, mostly short range line of sight. I was looking at the Cardo Freecom 4, as that is probably the most and everyone can talk at the same time.
Schuberth C4 Pro with the SC1. Excellent sound from the SatNav for directions, music and receiving phone calls. Can swap batteries, although they usually last me at least a day with only directions (SS1000 days)
I ride alone, to be together......
No use for intercom function.
Another YES for the Schuberth C4 Pro with SC1. The big plus for me is in having a spare battery. On an SS1000 I'll be listening to music/podcasts the whole journey. The spare is slotted in at about 9 1/2 or 10 hours. I can also receive phone calls en route.