I've had 2 males and 1 female boxer over my life. The second male and female were together.
The males were less mental than the female!
All of them were great around kids.
The second male loved obedience training and agility.
The female....nuts....too busy saying hello to everyone!
The first male died at 13. He was black and white and amazing to have as a child
He had reoccurring cancer which needed almost annual treatment. He was my childhood love.
The second male died at 6 of cancer, with no warning. He did suffer with his stomach and it took a raw diet to sort him out. This can be expensive, especially with the vet investigations and different food trials.
The female died at 8 from bone cancer. She was expensive with vets, cysts, ACL tears, lumps and bumps, tests and surgeries. She became uninsurable.
The female did become aggressive to other dogs in the months before the male died. This improved once he had passed. However, she was strong, and I had to walk well away from other people during her aggressive period.
Boxers are prone to cancers, hip issues and the like.
I'm still wishing for another though. Nothing fills your heart or home like a boxer does.
My advice would be research, research, research. If you can Joeys Boxer Rescue Liverpool have plenty of boxers waiting for homes. If you want a puppy make sure you go to a reputable registered breeder and check bloodlines and health history. Although this isn't always a guarantee.
Good luck.