What do you like best?
I think where cubby shines is in its ease of use, and amount of storage. I can only speak to the free tier, which allocates you a whopping free 5Gb of cloud storage (as opposed to just the 2Gb offered by Dropbox) - 5 is always better than 2 (well, almost always).
The average user should be surprised how quickly they can hit Dropbox's 2Gb limit. With cubby, you're a lot safer for a lot longer there.
So, back to it's ease of use. I have native cubby client app's running on both my Mac & Windows machines, and sync'ing files all over the cloud in my "cubby" is brainless. A shared, cloud folder is a great thing to have.
What do you dislike?
The basic plan features are a little limited, but it's hard to complain when i'm not dishing any money out for the product.
Some of the pro features - like the DirectSync, which syncs folders across multiple computers & does NOT count against your cloud storage - would be nice a basic feature (though, i wouldn't expect it).
Recommendations to others considering the product
Though i am not personally a paid customer (nor am i a paid Dropbox customer), i think the Cubby Pro features are an attractive option.
What business problems are you solving with the product? What benefits have you realized?
I don't think we're realizing huge benefits here, though we are saving some valuable time by not having to manage a cloud storage device/server for individuals in my group.