They truly set the bar. Sony however still lacks sometimes, regardless of whether or not the hold patents for bluray (which really doesn't apply here). Rarely will an Oppo choke on something the Sony can play back. I'd challenge someone to that duel ;).
It really depends what you are after, feature wise, and what you are willing to spend. That's the main draw of the higher priced Oppo. They give you swiss army knife that's fully supported if you need help. For example, if things like dual HDMI output don't mean anything, then go for a more affordable player. They do offer excellent processing, but you have to do a side by side sometimes with the higher resolution formats to be able to detect really strong differences between players. Keep in mind 4K is a very new beast to the marketplace. Also, don't forget about the display you connect them to(!)