I would say now, watching it rise, and since I've talked to bitcoin miners that say almost half the network is now mining BCC... well, it's looking like there is a real split and you should hold both ;-)

It's nice to almost double one's holdings, by sitting on the ass!

https://coinmarketcap.com/currencies/bitcoin-cash/

Some estimate BCC goes to $1500 by end of month; I can imagine just to wait and see at this point ;-)