I have the original (I save tags in a box and I just went and looked).
Sooby has one in Hardiness Zone 4, which is the limit for these shrubs, so no wonder it is struggling a bit. I hope as it establishes it gets better, that really does happen sometimes.
I did cut mostly at the lowest nodes, but even the ones I cut below seemed to have nodes below the soil line so the whole thing grew furiously, immediately. I had suckering even before I butchered it. Last year I dug one up and gave it to my sister, it is a nice little shrub now.
It is interesting that the label says Hardiness Zones 4-9, also Heat Zone 6-9. I am Heat Zone 3 but these plants flourish here, just do not need to be baked in the summer. For our original poster in MA, The Hardiness Zone is how cold it gets in winter, the Heat Zone is how much hot weather you have in summer. Hardiness Zones have been used for a zillion years, but heat zones are new, maybe 15 years old so people are still figuring them out for each plant. Seattle of course is lovely in summer, typical day here is 75 degrees, sunny, and low humidity (uh oh, the secret's out, just 1-7 days a year over 86 degrees). You live in Hardiness Zone Zone 6, I think. Your Hydrangea should be happy there, not stressed liek Sooby's in Ontario. I also just glanced at the Heat Zone map. This puts you in Heat Zone 4 or 5 depending on your exact location in MA. Heat Zone 4 has 14-30 days over 86 degrees, and Heat Zone 5 shows 30-45 days over 86 degrees. But we all know people in Heat Zones 4-5 have lovely Hydrangeas, so the growers need to relabel their plants!
luis_pr- Yah, it is a topic of conversation among gardeners here, how much bigger everything gets. One of my chores this winter is to go out and remove almost everything I planted on the south side of my house. I spent a happy winter planning a lovely garden, relied on usual heights listed in my books. Much of the garden was supposed to be 2-3 ft tall, it is a 6-7 foot impenetrable jungle out there! I also need to get rid of some lovely Viburnums that are literally twice the height/width listed :-(