The MiG 21 was the epitome of simplicity when one considers that it is basically an engine with an elongated intake duct, a simple Delta for a wing and a place for the pilot to sit in.
She did he job well, and her's is a silhouette that will long be seen in the skies in the form of UAVs.
This was an aircraft that heralded the transition of fighters from being merely guns in the air to becoming a multi role asset.
You spoke well !
There have been a lot of talks and books about its capabilities. I think that this book solves all mysteries about its performances compared to Phantom's.
I saw it at eBay:
http://cgi.ebay.com/Fighter-Performance-Practice-Phantom-versus-MIG-21-/290443813778?cmd=ViewItem&pt=US_Texbook_Education&hash=item439fcce392