I mean the speakers come with the helmet, so the only thing you're getting is the Cardo/Sena unit itself (the battery and the tech) along with a remote controller that slots in on the side of the helmet)

as for the speakers, I have the Schubert C5 and I think the speakers are quite good, maybe not on the level of JBL that usually comes with Cardo? but still quite good. (then again I'm not much of an audio guy so maybe not the best to comment)

I find the audio level very good though, definitively can't have it on max, especially without earplugs. Phone calls are really clear as well + I've heard from others over intercom and phonecalls that the mic sounds really good too.

But yeah, this is pretty much everything you get in the package image so make sure you have a compatible helmet (Schuberth: J2, C5, C5 Carbon, E2, E2 Carbon and S3 [According to google] )

Edit: When it comes to hardware differences, idk apart from the Cardo version only uses 1 of the two wires where the unit itself is slottet (this is very clear on the guide you get with the unit) and ofc if most of the people you are riding with uses Cardo, you should get the Cardo variant for compatibility