I have two different types of carriers for Duke, one is by Outward Hound and the other is by Fido and Company. I prefer the Fido and Company bag, because it comes with a really nice, plush pillow for Duke to lay on, and there is no way that he can escape from this bag because it zips all the way up. It also has long leather straps, and a large leather side pocket so I will be able to place my passport, airline tickets, and boarding pass when Duke and I travel this summer.
The bag is also great for me to bring Duke into the office with me, because the flap lays flat on the ground and Duke can enter and exit as he pleases.
Although the Outward Hound bag is much smaller, I don't particularly care for it because being the little escape artist that Duke can be at times, he can easily try to jump out of the top of the bag -- yikes!
There are a lot of really great bags out there, so have fun looking for just the "right" bag for Esme.