Careful with the 128 GB version.
Your photos alone can easily run into the 20s of gigs. Music likewise. Then there's your mail; if you use GMail but read locally using Mail.app, it will download your complete mail. There's no way to just let the messages be stored only on the google servers. With multiple accounts, that can run into the 5-10 GB range.
Then there's iPads and iPhones. Backups are made, and these are usually in the 4 GB range. A number of them are kept on disk. It of course gets worse every time you get another model.
Apps nowadays are also in the gigabyte range. For example Pages alone is half a gig. And if you install something like Microsoft Office or Adobe software, don't be surprised when your Applications folder contains 15 gigs of apps.
Now there's all sorts of workarounds for the above, but you simply might want to avoid the above and just get a bigger SSD.