I think you'll be Okay.
Just prepare yourself to see an older person on the new passport than the one on the old passport.
We ran out of visa pages a few months ago and adding pages to the old passport was almost as expensive as getting a new one, so we went ahead and just did a renewal. We ordered the large passport with more visa pages. The old passports were only four years old but I was amazed at how much older, and fatter, the guy on the new one was.
The nice thing was that it only took just over two weeks to get the new passports.