Personally, I'd disregard the "if your kids are between this age and this age, then this restaurant is a one size fits all" advice.
I've done 'Ohana dinner, done the fireworks on Poly's beach more than once, done Cali Grill, done fireworks viewing on Cali Grill's terrace several times. I have two teenagers, and they've been going to WDW since they were about the age of your kids.
Thoughts:
1. California Grill (even with the menu change to prefix, which I am disappointed in) is head and shoulders above 'Ohana as far as food in our experience.
2. Atmosphere inside at both is nice, though different than the other. The vibe at 'Ohana is lively, and at Cali Grill it's more refined/classic but not at all stuffy and very family friendly (views are fantastic as well, even if your table isn't right at a window). We've found 'Ohana to be very loud and service consistently rushed. Out of our experiences at Cali Grill, we've had one rushed server, all the others have given us time to enjoy our meal, and they have given our table personalized attention.
3. The fireworks view at Cali Grill is amazing, more so in our opinion than the one at Poly. But the view at Poly was still outstanding.
4. Our kids (even when they were early elementary school aged) liked Cali Grill's food, atmosphere, and experience better than 'Ohana. They enjoyed being able to choose different options vs a set 'family style meal' where everyone gets the same thing. They enjoyed having servers who chatted with them and discussed menu preferences vs random servers stopping by for a second to put a skillet of dumplings on the table. The liked both restaurants, just found Cali Grill to be more special and memorable.
5. My kids are my kids and not anyone else's. I know lots of others that age would not like Cali Grill (frankly, a lot of adults wouldn't either). Everyone's situation is unique. So long as you understand the difference between the two restaurants, you can make the best choice for your family.
So in the end, I'm just saying don't write off Cali Grill because of the ages of your kids.