Actually the only extra features are Component and S-Video support, 1080p support, and Bluetooth controller support. Hardly $250+ of value.
+ Aluminum chassis
+ Far more capable FPGA (more features likely coming as a result)
+ Menu/config accessible as overlay during gameplay
+ Composite output
+ RGB output
+ Scalers
+ 4 color palette choices
+ Interpolation
+ No lag introduced on final display due to 1080p upscale
+ Far more accurate integer scaled pixel aspect ratio choices with 1080p
+ Image positioning
+ Zapper, Famicom mic, and 3D glasses support
+ Significantly more control over audio
+ HDMI EDID
+ Included bluetooth receiver that supports PS3, PS4, Wii U/etc controllers
+ Included bluetooth controller
Whether the extra features are worth the cost is subjective, but after watching used versions of the previous Analogue NTs consistently sell for $1000-$3000 on eBay, this new one seems like a relative bargain!