The 2i had better SQ than the 2
The n130 supposedly improved SQ a little, but it also introduced an HDMI input.
The n132 offers slightly better DAC, HDMI and DIRAC live support and they changed the headphones jack from 3.5 mm to ¼ inch.
I have a 2i on my basement system.
I have a n130 on my main system where the 2i used to be. I did notice a slightly more refined sound when I upgraded.
I've always used an external DAC so I can't speak to the DAC changes.