To be honest, the only person who can answer that question is you.
What value do you put on your miles? What enhancements in service are enough for you to say that you received good value for those miles?
If you have never flown CX F, then my suggestion is, "go for it." It can be a hard redemption to snag if you're not MPO Gold or Diamond, but if you do luck out, it's a lovely way to fly.