Too late for me to edit, but the Analogue-NT Mini is also FPGA. I got that wrong. Pretty sure the original NT was fully hardware, not FPGA, but I don't think it's available anymore.

Main difference between the two linked products, then, aside from appearance and maybe build quality (can't say which is better, don't own either), is output options, as best I can tell (the NT has a lot of AV out options). And price, obviously.

[EDIT] The reason video out options are important, aside from aesthetics, is that some peripherals require a CRT. Notably the Zapper.