The 250 model Samsung evo also has higher read write speeds compared to a 120, the speeds increase up to the 500 GB model I think.
I think in the big scheme of things its not going to make a massive difference to you unless your going to use the new one for games rather than a HDD etc.
Personally I run 2 Samsung 850 evos 250, one for windows, one games and have a USB 3 external HDD enclosure to store my back up's on that's only powered up for tasks to avoid start up delays.
Seems to work well for me!