Being a barebone version of the 5 Series, I would imagine D5003 would also use the same panels. Haven't seen the D5003 but you should check if both menu's are the same. If D5003 is more basic, don't get it.
Also, its USB player does not have video playback, let alone HD like the D5000.
Basically you should only consider it if you have an HDMI AV receiver, and if you have/need an HD media player. Or if you only intend using one HDMI device at a time.