I personally would toss it. I assume that as you have a thread there is an element of trade value that you need. I'm very certain that there is a perfect Celebi out there.
I've just got mine at last and I had at least two 31/x/31/31/31/31 spreads with either a neutral nature or a special nature. I also had a tempting Impish one 28/31/31/x/31/31 which I tossed.
Your standards are your own. How much patience you have and how much real-life stuff will always play a part.
Yeah think you're right. But honestly, is the first softreset and I've done this in less of 200 reset. Obviously there is in somewhere on this planet a perfect celebi, but as first tentative i think is good enough. Thanks for your opinion, I appreciate it :)