Oh! I love your bag! I'm eyeing this from the 23K collection too! Still waiting to hear from my SA...

no news so far...
So, if you ask me, here's my completely BIASED opinion (haha). Keep it. Tweed is so classic Chanel and this is in black and white. You can't get more classic than that! I've been waiting for a good tweed for a while now and this is one of the best tweeds IMO. It's classic black-and-white and will go with a neutral wardrobe. I am also extremely partial to the adjustable pearl crush chain. It can be a shoulder bag or a cross body bag - you choose!
I only have 1 tweed bag (it's a 19) and I've had it for just over a year. I have no issues at all with the tweed. No pilling, no snags. I am careful with it and it's not my "throw around" bag. Since you said you baby your bags, I'm sure your tweed mini will look good for years to come. That said, every tweed Chanel makes is different so I'm sure some are more delicate (eg: the ones with sequins or ribbon threaded through the tweed) and will probably need more care. But yours looks hardy and durable!
Have you decided to keep the bag?