I'm not a fan of up-the-middle, galley type accesses like Boreas has. Much prefer side entrances, but that's a personal thing. What I can tell you is that it's my wife, me, a 60-lb Malinois, and a 70-lb Dutch Shepherd and there's tons of space in our G12. If we're all inside due to crummy weather, the dogs happily chill on the bed while there's plenty of seating for the wife and I (and more). Or tons of room to take a nap/read in bed/etc. and move about. At bedtime, our Mal sleeps between us, while the Dutchie gets the long bench to sprawl out on. We, rarely, use the table. And when we're done eating or working on it, it gets stowed on top of the long bench under the cabinet.
An advantage with the EOS is the lower bed height. Easier ingress/egress, with the downside being less storage...the G12 has an insane amount of storage. Conversely, our Mal is over 13 and it's getting harder for her to make the leap up onto the bench, then, again, up to the bed. I also use a collapsible baby gate in the middle of the bed to keep them from jumping straight down to the floor (I do the same in our OVRLND truck camper.
There are a number of reasons we went with the Arkto after first seeing the EOS, but this is, probably, the most relevant dog/interior space feedback I have.