FYI- the CURRENT '15 software can work on '14 radios. the only thing that doesnt work is that they apparently also changed the media hub (which is just a USB device) and they didn't include the '14 drivers in the '15 software. If both sets of drivers were included in teh software image then one version MIGHT be able to work on either.
Customtronix has gotten it to work. Various "average joe's" have accidently installed the '15 software and it runs but fubar's the gps apparently.
So at the present time it looks like the only reason the 14's haven't gotten the same features as the 15's is a choice FCA made. It's possible future features that haven't been enabled yet would require whatever new hardware is required in the 15's. (although since the only different feature seems to be a monthly report i guess maybe there's a can bus interaction that might be missing on the 14???)
As far as memory/storage- the original (aka 14) hardware had a pretty decent chunk of storage- so not sure that would be a limiter just yet. Also Customtronix has stated it's 'the exact same hardware'- I suspect the things they can see by diggin in the QNX OS like processor, memory, etc are the same but there's some other hardware in there that has a new revision- for example seems the GPS is different since it gets borked when you put the 15 software on a 14.
The 14.25.5 software looks to be well under a gig. The map database might be 3-5 gigs (not sure anyone has posted yet). 2013-2014 UConnect 2: the next generation
says the 512MB ram and 16 MB of storage as an example. So storage doesn't look to be an issue. I guess the memory could be if just 512 but we'd have to figure out if the 15 really does have more or not.
if someone has a couple extra g's floating around they can buy one of each and then compare the chipsets and we can see if there's any obvious differences. That might confirm that the CPU/SOC, memory, and storage are or aren't the same. But unless they are stamped with different info i'm not sure you would notice a change in sat radio, gps, canbus, or other special purpose sort of chips.