I have had quail now for over 7 years, but only as pets and not to process, and mainly because I was never able to have chickens so they were my substitute. I moved to a 2+ acre lot where technically I'm not supposed to have chickens, but I'm surrounded by farms and have no close neighbors, so gave in last spring and got 4 chickens. Before the chickens I really enjoyed having fresh quail eggs and had family members begging for them, but now that I have chicken eggs they think the quail eggs are too much trouble and don't want them.
I've also learned not to get attached to the quail as pets, even though I hand raised a group this year. It seems that your favorite is always the one that suddenly dies, or the only ones that escape or get killed are the females when you've got extra males around being noisy that you'd gladly give away if someone would take them. They'll be fine for weeks/months then all of a sudden someone bashes their head while bouncing up, everyone sees blood, and chaos ensues with you having to separate them out until they can heal.
I'm sure it would be different if you are doing it commercially, but be prepared for quite a bit of work and loss. I incubated 31 eggs and had 6 not fertile, another 7 not hatch, and out of the 18 that did hatch had to work with 4 of them as special needs. They drown easily, they break their necks easily, they overheat easily, they waste tons of food, and if you raise them outside basically everything wants to kill them. I'd thought about trying to sell eggs to local restaurants, but don't have the volume of birds to be able to do so nor the desire to get licensed/inspected to be able to sell commercially.