I'm pretty sure the 2012 freeride was based on the XP chasis, the 2013 Is going to be on the XM body, totaly different animal, If I was buying a freeride I'd for sure spend a little extra & get the 2013!!
The RS chassis heavier. I do not know how much more just the chassis is but as an example the 2014 154" XM has an advertised weight of 459 and the Freeride 154 has an advertised weight of 489.
Part of that 30 pounds is due to the chassis, part is due to the better and heavier shock package.