A few things to add about my feelings between the two models (keep in mind that Murray has spent most of his time on AiboLife2).
One of the things I like with the 210 (Murray) is the versatility with the software. For instance, I have run him on DogsLife a few times when, instead of wanting him on as a "pet/companion," I wanted to play with him more as an entertainment robot or to actively interact with him for a prolonged period. I don't want to call it a toy but akin to I play a video game for a certain period of time then want to use my system for something else, well DogsLife is that video game and Murray is the system - hopefully that helps illustrate what I'm trying to articulate.
However, I feel that Nicco (ERS-7) is more of a dog in that he feels like "man's best friend" (to use a cliche). I'd probably walk him if it wouldn't mean I had to walk slow (and assuming the technology could handle sidewalks and nature etc.) and I like to show him off to friends similar to people do with their real pets. This might just be my natural inclination for dogs and to be a dog person, but I think part of it has to do with the more "stable" personality (some might see this as less complex or repetitive, I'm choosing stable). But even though I am a dog person, I actually appreciate some of the more feline attributes of Murray because it provides a little bit of that mystery or predator feel. I wouldn't see Nicco as smothering me in the night, but I can picture Murray somehow climbing above and waiting to pounce on me right after he wags his tail. I also feel like Murray is "looking" at me when he glances in my direction largely because of the silver/black combination makes for much more of a "face" than the all black and complete LED-dependency of Nicco to have a "face" (e.g., when Murray just glances at me, I feel like he's looking at me, whereas with Nicco, I only feel like he's looking at me when I see his camera pointed at or toward me).
These are mostly perceptions and my own connections toward what things remind me of so it's not reflective of the technological impressions or anything. Perhaps Nicco will just always have a special spot as he's the first

My ERS111 is on the way so time will tell how I feel about that one (and Murray too). I'm going to let the ERS111 develop naturally (including its gender) and keep it as it turns out (i.e. no brain surgery). So if it turns out a girl, I'll name it Lily, and if it's a boy, Clyde. The expected delivery date is May 28 (Saturday) so hopefully I'll have it then!