I wanted older chickens and used Chase. We got four pullets. One of them ended up being a meat bird rooster (a breed that she only sells straight run). I'm not an expert but it seems like you should keep your straight run birds separate from your sexed birds and your laying hens separate from meat birds. They were all fully feathered birds and all were going through a juvenile molt. No big deal, but you think she'd be able to tell her breeds apart when they are fully feathered.
The birds were sick when I got them and I had to treat them all for cocci. They all survived and did well. Then we realized we had a rooster and were trying to rehome him, but the rooster ended up getting sick - he lost the use of his legs and eventually died. When I contacted her indicating she might have a serious health problem in her flock and with my concerns about not keeping straight run meat birds separate from sexed laying hens I got no response. Obviously we aren't sure what the rooster had, but I probably can't get chicks that aren't vaccinated for Mereks in the future.
As a side note (now that I know a LOT more about chickens) I read back in some emails to her when I asked her about vaccinating her chicks. She said "I leave it up to the individual owners because it is controversial". Now I know that you only have a short window to vaccinate in and it isn't something that can be left up to the people who buy her chicks.
Anyway, all of what happened is OK and could happen in a lot of scenarios but I'd probably take my chances elsewhere especially where I don't live in the SLC valley and had to drive a distance to pick up the chickens.