Several years ago, I bought a couple Kieffers from TSC and was very disappointed. When I pulled them out of the pot the soil fell right off to reveal a stump of a root ball with all of the root shoots appearing to be broken off. It looked like someone tore the tree out of the ground the day before and stuck it into a pot filled with potting soil. Neither tree lasted more than a month.
On the complete contrary, I have had great success with Kieffers and apple I have bought at Lowes.
Now, I don't mean to throw down on TSC. The trees looked great in the pots and I am sure their buyer saw the same thing that I did. Having said that, I never bought a tree from TSC again but continue to buy from Lowes without any issues. But, I think my point is that it may be a hit or miss situation based on the nursery they got them from.