The VDR product was manageable via a plugin on the vSphere Client (the Windows one), the VDP one is only manageable via a Web Client "plugin". Both are Linux based vApps, with VDR was CentOS and with VDP it's SUSE.
I ran VDR for quite a while with mostly good results, but VDP causes nothing but problems, it's not a solid solution for VM backups and the interface is awkward to work with.