I've never bought seedlings out of seed catalogs, but am sometimes tempted to (especially by the flashy free $20, no obligation seed catalogs).
I'm just wondering what the considerations are when ordering seedlings by mail. I worked in a postal distribution center once and I don't think we would have taken too special precaution not to disturb the roots of any box (although we tried to be very careful when someone sends baby chicks). Not to mention the unnatural darkness of the mail truck and the time it takes to get from place to place, the possible pressure changes caused by driving through mountains or air mail, etc.
Anyway, are mail order plants OK or should any be specifically avoided?