I would definitely go ahead and try to get an ADR for Le Cellier. Here's my reasoning: We have had success getting a last minute ADR for Jiko, but Le Cellier ADRs are impossible to get. So, if you eat at Jiko and love it to pieces, you can cancel your Le Cellier ADR and hopefully snag a Jiko ADR with short notice. The reverse is not true.
Now, we've travelled in January, not October, so free dining may throw a monkey wrench in that plan. But I stand by the idea that you'll have a better chance of snagging a last minute ADR to Jiko than to Le Cellier.
ADR logistics aside, we enjoyed Le Cellier. We like the atmosphere, we loved our server, we loved trying Canadian wines, and we enjoyed the food. We would go back there again (ADRs allowing) in a heartbeat. We did not feel it was overhyped. Is it the best restaurant at WDW? No, but it is a great experience.
Jiko is a stunning restaurant. The appetizers and desserts are to die for. We have never been impressed with the entrees. BUT, if you're staying at AKL, I would definitely give a try.
Also, since you're staying at AKL, you must do the Culinary Tour of Africa. It's basically a (FREE!) mini tour of Boma and Jiko with tastings at each. At Boma, we got to taste two soups (on Thursday, they had Potato Bacon and a Cream of Mushroom). At Jiko, we tasted this:
Taste of Africa - Trio of Dips with Assorted Breads and House-made Naan $9.00
There were only about 8 people in our little tour. I think they do it every evening, and again, it's FREE!