OK, I said I'd never do it, but I decided to get a grip for my D600. Since I had pretty good luck with a 3rd-party grip for my D7000, I did the same for my D600. I don't shoot much using a grip, since I normally shoot landscapes and macros and having the grip for that is more of a hinderance, I liked having the grip for my D7000 to shoot candids.
So I dropped the dime yesterday on a 3rd-party grip from ebay. Total cost: $49.20.
I'll post the results when it arrives.
I hate when people ask me what I see myself doing in 5 years...... I don't have 2020 vision!