This is where it's necessary to think about what you want from a rooster and where you want your flock to go in the future.
Are you going to hatch your own eggs to renew your flock? In that case, remember that the rooster is half the genetics.
If you want nice table birds the rule is to breed the one you want to eat -- the chunky, meaty one -- because that way each generation gets better.
Only you know what YOU want, but here's what I did when considering birds.
First, temperament. I have no room in my flock for a jerk.
Second, decent type for the breed. I had a really BEAUTIFUL yard ornament among my 5 males last winter. Fast maturing, pretty color, and glorious tail. But he was horribly bad type for an Australorp -- leggy, lanky, and narrow. So he was the first out of contention.
Third, I wanted early maturity. I'd had a slow-developer in Ludwig, the Black Langshan -- which is normal for his breed. But Australorps are supposed to be early-maturers so I didn't want a slowpoke. That put a bad mark against one of the other 4.
I also wanted good size. I know that hatchery birds tend to run below SOP for their breeds. At that point I was also considering good coloration.
After getting photos evaluated by some experienced people I had 2 solid candidates and a "maybe". That was when I started feeling them for width in the back and chest and weighing them.
I also watched their behavior. One of them was dancing for the girls even at the tender age of 15 weeks. They weren't impressed, but he was trying.
A few weeks later I knew that he was also a better-colored blue than the photos in the hatchery catalogs.
I had one last hesitation because the competitor was just a few ounces heavier. And I took a bunch of photos, including this one:
You can tell from my avatar which one I chose and, despite the blurriness of the action shot, I think you can tell why.
Green-band, now Rameses, was simply a better bird.
You don't have males of the same breed and you don't necessarily have the same goals, but I think you can follow my mental process there. Figure out what you want and figure out what each male offers.