I like to study at Leone. The drone of the patrons and restaurant work well for me, and I've always been able to sit near an outlet.
I've only ordered plain coffee and (once) a bagel. Neither were disappointing (or superbly fantastic, I suppose). What's great about Leone is that the server is fantastic at doing rounds and always clears your plate and refills your drinks in a timely manner.
The gratis water infused with fruit is also delicious between my cups of coffee.