I have a luna that I haven't had a chance to use yet, but I have used my Cucciolo on the way back from a trip, and it fit alot of my carry on junk - purse, magazines, book, iPod, Sirius stiletto, snacks and a drink. I also use the Cucciolo to take my lunch, purse, light sweater, portable radio/iPod speakers and all the cables and remote, extra snacks and sometimes a bottle of water and random book or notebook to work every day. From what I have read, the Trenino is supposed to hold a lot more than the cucciolo!