My chevron started out as about a 1.5 to 2.5 inch fish. Fairly small. Now about 6 months later. It's probably a good 4-4.5 " in size. If he grows that much in 6 months, or less, then I expect it'll be 8-9" within a year. I have him in a 125.. He's become the dominator of the tank. My 3 largest fish constantly swim up to each other side by side to see if any of them are bigger than the other yet. I swear they'll like kids.. "I'm bigger than you.. Oh wait, nope, you're still the same size, just wait.... I'll be beating you up later..."
They swim off and then rinse and repeat several times a day.. They must forget how big they all are.
In general I love my chevron. However, he's been a ****ant to other fish. Some fish he dominates, other fish he couldn't care less about. I'm not sure how he decides! One of my fish not sure if it was the chevron, chewed the tail off my sleeper goby. I've got a tiny rainford's goby that no fish ever touches.. Go figure...

. I have a starry blenny, doesn't act much different than the goby, just lays around, and no one touches him. So why target the sleeper goby? Don't know.
I love the Chevron, it's been hardy, it's a great eater, and at times is mean, but seems to be o.k. with everyone now.