I can't say enough good things about the plants I've received from Bluestone!

They are definitely bigger than the 3-pak. I would guesstimate they are about the size of a standard 4 inch pot, only taller. I got the loveliest pieris in the big sized pot and it's growing like gang-busters!

In my opinion, it's a great deal for shrubs, if you don't mind growing them on for a awhile. For perennials, maybe not so much. I have a local supplier who sells the same varieties (ie. phlox "Flower Power") for only a dollar more ($8) in a half gallon container. YMMV.

Please don't interpret this as criticism of Bluestone - they are my favorite online plant seller, bar none. I think I'm just lucky to have such a great local vendor! ;)