Pros
Cheaper than the FPGA clones i was considering.
Less input lag than original hardware.
Awesome CRT shaders.
Retro achievements.
Use just about any controller in the world.
Play awesome hacks.
Also emulates any system up to the PS2/Wii.
Can be a filthy pirate and save money on over priced pieces of plastic.

Probably more but i'm heckin tired.
Cons
Can't play my carts. Well, i COULD if a bought a Retrode.
Not a NES
If you really want to play actual carts, and don't want to spend hundreds of dollars on an FPGA clone, i would just get a real NES and a RetroTink2x. Clones suck. Retrons SUCK. You could also look into the MiSTer FPGA.