I've got some, they just turned 6 weeks old. I'm pretty happy with them. They have been vigorous & growthy. We put them outside at 3 weeks, in some of the hottest weather we've had in Oklahoma in many years. They managed just fine in the heat. They are really active and are very good at foraging. Not so great in figuring out how to get up the plank into the roost at night, though. It took them a while longer to feather out all the way, too, compared to our layers; I figure they were putting the protein into growth and muscle deposition. They pretty red birds now, though.
We wanted an alternative to CX, and are satisfied with the red broilers so far. At the rate they are growing, I have no doubt they will be a good size when they go for processing in another 6 weeks. No, they don't grow as fast as the cornish x, but we wanted a slower growing, tastier bird anyway. I'm also not too interested in the hugemongous breast meat (rubbery!). A lot depends on what your desires and goals for a meaty flock are. I know there have been some folks not so happy with red broilers; others that prefer cornish x. It's all rather subjective.
Good luck!