I have never had a bad experience with McMurray or the birds I have gotten from them. They always include extra birds and I have been pleased with those as well (not the free rare chick either, I mean the extra packing peanut chicks lol).
From my previous order I had 2 little barred rock pullets that did not do well. They seemed sickly when they arrived. McMurray gave credit on them and all the barred rocks for our troubles. Which I felt was extremely generous although it was sad the little sick chicks were not culled initially when the order was packaged for shipping. It was obvious something was wrong with those 2 from the start. They did not make it through the day when they arrived.
I think the success with the chicks from any hatchery is also in the planning of your purchase. It pays to be concerned about the weather and getting the chicks at a time when the weather is not too cold or not too hot, also when it is not too damp or rainy. I have tried to plan for good warm weather, moderately dry but not excessively humid. It is a hard call sometimes.
This is the first time I have gotten the jumbo cornish x so I am curious as to the outcome of these. Our weather is still very warm, unseasonably so for October - low 90's. Very odd. But the evening and morning air is cool and feels like spring instead of fall. If the weather holds out like this for another week or two I won't be concerned too much with their health. It is ideal weather for baby chicks here in central Va., nestled near the foot hills of the Blue Ridge. I have set a small run away from the large coop and these chicks will get a chance daily to run and play in the grass.
With that said I am trying EXTREMELY hard not to see these little guys as the holding making a pet out of chicks. It would be far too hard to follow through with the end result if I did. But it is so hard to resist not reaching in and playing with them.
Happy chicken raising everyone!