Advice Please

Is there any particular reason why you haven't used the flap? If its that you prefer using your GST, then you should probably sell the flap.

However as has been mentioned here, quality control seems to be getting slacker, you might find if you are to repurchase a flap later the quality is not as good, but with an inflated price tag.

If you use the GST on a regular basis, maybe for a week you should try using your flap, and see how you feel about it afterwards!
 
Keep the flap. Prices always go up on them and you can have it forever. How comes you dont use it? Do you not like it? At first I didnt like flaps that much and went for more funky peices, then I bought tons of flaps and now am back to liking the more bigger fun bags. Think about why you dont use it and then it should be easy from there.
 
I love both bags and I guess /i have been saving the flap for special occasions instead of using it. I think I may just get rid of some shoes. I think I would regret selling either Chanel since they are so beautiful. The flap quality is superb and I know the quality is going downhill, so it would be a shame to sell it. I just need to stop babying the flap and use it!