I can really only echo what other people in the thread have already said. While I personally like Retro more than I liked Rare (I loved some of their games, but was lukewarm on some - I've loved every Retro game so far), Retro's pace is extremely slow even by today's standard. It wasn't at first, but since the first Donkey Kong Country game they made, they've been extremely slow.
And the excuses that they'd be faster if they were bigger, well ... They've expanded twice since their last game release and Miyamoto went on record 2 or 3 years ago saying Retro were now big enough to work on two games simultaneously.
Hopefully whatever they're cooking up is extraordinary, because they've sure been keeping us waiting.
Looking at Rare, in comparison, they pumped out titles at an extremely rapid pace (which, admittedly, is not feasible in today's game development climate), and they also got to both experiment with their own ideas, work on classic Nintendo franchises and even use high-profile IPs (James Bond).
Across a 8-year span, Rare gave people great games in platforming, collectathons, kart racing, FPS, fighting and more. Retro just doesn't match that, even if I happen to like their titles as a whole more than I like Rare's as a whole.
With all that said, Rare really does not exist anymore, and Nintendo cutting them loose when they did was perfect foresight. Hopefully we get to see more amazing stuff from Retro in the future, they haven't streered me wrong yet.