Jagdish, I think the comparison is a little unfair to both parties.
The Oppo BD-83 has been designed to be one of the best universal players and optimised for Blu-Ray and FullHD. It also has circuitry very similar to the Oppo 983H that allows the player to work as a CD Player. It has a high end video upscaling engine.
Dune started as a regular media player. It uses the same Sigma Designs circuitry as nearly every other player does. It has capabilities such as eSATA port, Ethernet 100/1000(*) Mbit/s, WiFi, and upcoming RF support. It can read ALL the files of a external drive and can use network functions such as SMB, UPnP, NFS, HTTP media streams, and FTP. In terms of Pros, the Dune has minimal upscaling features and cannot process HD Audio. It cannot play SACD or DVD-A discs.
The Oppo, on the other hand, has one of the best audio and video processing engines in the world at it's price point. It has limited network capabilities and can read external HDD only to a limited extent. It can process HD Audio and can send data in analogue format to external AVRs.
If you want a capable Universal cum Blu-Ray player, Oppo is hard to beat. Dune is a good media player. But in my mind, at least in India, it is too expensive at around 36K when you get media players using the same Sigma Designs circuitry at around 10K.
Cheers