If you're weighing your option between SSDs and you can't quite justify buying the bigger version, this might tip you over the edge: Generally, larger SSDs are also faster. Photo by [email protected].
As the How-To Geek explains, SSDs function using NAND chips, not the spinning platters of HDDs. In order to add more capacity to an SSD, manufacturers have to add more chips. When they do this, they usually arrange those chips so they can be used in parallel. In other words, a larger SSD can write to, say, eight NAND chips at once instead of the four that a smaller SSD would do.
This gives a speed advantage to larger capacity SSDs in terms of data throughput. While your mileage will obviously vary based on how a manufacturer built the SSD and how big of a capacity difference you're looking at, in general the smaller an SSD, the slower you can expect it to be. Though it will still be faster than most regular hard drives.
Why Are Smaller SSDs Slower? [How-To Geek]