My first thought was similar, though followed quickly by "...but it's Apple, so what's the catch?" The relevant extra things to know are that the SSD is soldered, there are no slots for extra SSDs, and choosing a sensible (1TB) drive is >4X the price of buying similar storage at retail. Still a no from me, then.

(The only thing I do often that's CPU-limited is compiling, being faster at that saves me maybe a few minutes in a full working day; I don't care. I am frequently limited by RAM and I really hate shuffling things around to make space on drives.)