Get a new changing pad or not?

Is

My baby is almost six months and he's almost grown out of his changing pad, is it worth it to get a new one? We have a changing pad with "walls" all around, if that makes sense? I'm thinking of getting one with only "walls" on the sides as he's getting so long. For how long did you use your changing pads? We have a changing table in our bedroom and it's really convenient, at night for example.