Actually, it's very good. You just have to slow roast them at lower temperatures. If cooked too rapidly at too high a temperature they can be somewhat chewy. Some people skin them prior to cooking, but that is not a good idea as it seems to allow the meat to dry out.
On your other post, you said you're selling them because the male is mean. It is common for birds with attitude to end up as dinner. I understand that may not be a desirable outcome for your birds but it may be the best end rather than some of the other options like someone being cruel to it and abusing or neglecting it because it's mean, using it for dog training, etc. When we sell an animal, we have no control over what happens to it once it is out of our hands. It is no longer our property and the only way we would have a say in what happens to it is through a legally binding contract (i.e. breeding rights on dogs, spay/neuter contracts, etc) or by retaining partial ownership. I know it's hard to sell animals that you are attached to but truly the only way to control what happens to them is to keep them yourself.
It is tough when you raise an animal to think that someone could eat it.
When I was young, I had guineas and they were my babies. I couldn't stand for someone to eat them. When I went to college, I gave them 'back' to my great uncle (he gave me the original breeding pair). They wandered away from his flock as their own flock. Two weeks later they were fine. Four weeks later they were feral, because no one could spend time getting them to stay home. Five weeks later one was left, Razz I think from what they said, and then she was gone.
I did not do well by my babies.
And even before that mishap, one of my younger guineas was just mean. He terrorized his father and kicked him out of the flock after beating him up. He was forced on the edge of the flock and only wanted his mate. I put the two together, but the mate was miserable. I let them out and the male got hung in a fence. A few months after that, and losing my birds at my great uncles, I swore to cull any mean birds.
If you don't have the resources to provide for your birds (enough space, numbers, or separate enclosures where they are *content* and *happy*) then you must cull. The mean one can't stay and terrorize the rest if you don't have the means to stop it.
A quick death and a meaningful death is far better than other disasters that could result.
If you aren't vegetarian, I promise you that most the chickens you eat had it rougher than you boxing up your bird for someone who is experienced in slaughtering poultry and will kill him the same day. It's tough, and it's sad, but one way or another you have to find a good solution.
I now am raising guineas for meat (and a few will live for eggs and producing next year's birds). I love them, but I choose to eat meat and I choose to raise my own rather than always deal with the commercial poultry industry.
I hope that helps. I'm not meaning to lecture. Just provide an honest viewpoint and a real world perspective. *hugs*