Thought I'd let everyone know I went naked yesterday! Also, I used my phone without a case all day ;-)
Day 1: Phone appears unscathed. Case is back on today until I can once again muster the courage.
I'm trying caseless today myself. Though mine already has some slight scratches on the back.
I would be more inclined to go case less if my phone had scratches
Honestly, it's not the slipperiness of the back that worries me, I'm conscious of that. It's the sides can be slick.