THIS IS A HORRIBLE QUESTION!!
(LOL I joke. But really though.. bawls over both my dogs.)
I'd choose Rara. She's so intelligent. Her mind is very unique, and I don't think I will ever have or even encounter another dog in my life as deeply intelligent, observant, and human-like as Rara for the rest of my life. Just imagining the extent of which she'll understand human language and math and the universe after living for 20 years or so, I'll probably need to turn back into a caveman to make room for her. LOL.
Her level of intelligence is as eerie as I make it sound, yes. I think she might be an alien of superior race from outer space come to spy on us dumb humans.
Lancer is a typical Aussie. Sensitive, yeah, learns tricks/commands super fast, hard-working, driven, and I'd say an all-around also very smart dog. But he's still clearly just a dog when placed next to Rara.