Yeah, there might be small differences.
The Tolino Vision 6 (equivalent to the Kobo Libra 2) also uses the new quad-core SoC instead. As a matter of fact, all current Tolino devices are now on the new chip.
I wish, the Shine 4 would also use the older SoC though. At least that would take care of some of those battery issues... Did you notice, how under "Battery capacity" they only speak of just "several days" now and not "weeks" anymore?
Maybe Kobo does not want to develop the (android based) Tolino firmware for two seperate SoCs.