That is a very good buck for your client Clay!
Axis hunting is about as addictive in my opinion as any I've done, even when compared to Africa. Mature bucks are regal and elusive animals, they vocalize through their roaring which makes the hunt more fun and engaging, they are plentiful and huntable year round in a large area of the great state of Texas, they are one of the prettiest critters you'll ever hunt, and the meat is top notch eating... there's just a lot to like about chasin' them!
I have hunted them a whole lot since going after them for a few days with Clay and the PBGSO crew several years ago, and they've become my favorite animal to hunt east of the Rockies. I'm no expert but I try to learn as much as I can about them, and I have come to believe that they can be "guessed at" on about the same level with whitetails. My uneducated guess is this buck is probably 6 or 7 years old, possibly more. That is definitely just a guess though.