I have the older version of this one in the small size:
Element | Sherpa Pet
The bottom is made of wood covered in faux sheepskin. its easy to removeand clean. I think it just makes the pup feel more secure to have a truly solid platform versus some of the more flimsy ones.
I like the way both ends plus one side is vented, it keeps things nice and cool. The solid side has a strap that you can secure a seatbelt through in the car for travel.
The material is sturdy and easily spot cleaned. The handle is long enough that you can put it over your shoulder to carry, though its not the most comfortable.
I bought mine at Petco, so I was able to see the fit and construction before I paid for it. Overall, I have been very happy with it.