I wouldn't say the HM5 pads have the exact same sound as the stock pads, they are very similar though. The HM5 leather pads are definitely more comfortable to me as well. They are quite deep and are pretty soft. Right now, I definitely prefer the HM5 leather pads to the stock pads and it does feel like I get a better seal with the HM5 leather pads as well.
Here is a quick pic of the HM5 leathers on the D5000:
Sorry for the quality. I will take better pictures later.