Honestly, I bought the s1 used "like new" for $1600 earlier this month. It came with v-log too!
If the new s5 is $2000 (assuming) new then I still think the s1 was a much better buy.
I like big camera bodies and it's one of the reasons I got an s1, although a small reason, it still mattered to me. I wanted a tanky daily driver work horse of a camera! Something with great battery life, a bright screen, big body, good evf,
So after thinking about the s5, it honestly doesn't really sound like the camera I wanted anyway, the s1 literally is the camera I wanted, so I'm happy with my purchase. I learned I'm able to return my s1 if i want but I'm choosing not too.
4k 60p 10bit is neat, but I hardly even care about 4k 60p, even then, 8bit 60p looks fantastic!
I still think the s1 is the nicer more professional camera overall and its used prices are so good that it wins against the s5 when it comes to cost. Again, assuming the s5 will be $2000.