In this hobby, you'll find that most people want something that looks nice as well as performs nicely. I'm not saying a DVD player can't perform well, but to my knowledge there's no such DVD player that has the form factor, finish, and operation of the PD-H300 other than similar offerings from Teac. The differences can also come down to quickness of operation. Most small DVD players are slow and I've always felt that they've lacked in appearance and quality.
Just to illustrate my point, where are you going to find a DVD player that is not only compact like the PD-H300 but will also have a large, easy to read, florescent display?