which should we gIve priority?
- SNR can effect CCQ value,
- Signal from multiple path can also effect CCQ.
- Low signal effect CCQ.
A good link is a link that has highest CCQ value possible.
The CCQ is derived from the amount of retries. So if a link has a poor SNR, some packets may be received in error, so there will be a retransmission of the packet until it is received OK. Each time a packet is retransmitted the amount of ‘new’ traffic that can be passed falls. Therefore in turn, the overall link speed or link bandwidth falls. Therefore the CCQ number will fall to reflect this. 100% is perfect. I.e. all packets are received first time, every time.
You can have a link with a poor SNR with a high CCQ (if the link has no interference). On the other hand, you can have a link with a high SNR and a poor CCQ!
So the answer is that BOTH are important! 
Ron