I hadn't previously heard about Starbucks Reserve, so found your post very interesting. After a quick Google search I found that I haven't heard of it because we only have one Reserve store here in England, which is of course based in Central London.
Next time I am down that way I will have to pay them a visit and judge for myself 😊

I would be interested to see if you notice a significant difference between the Hazelnut Latte at the Reserve store vs a regular Starbucks. Perhaps you can give an update when you get the chance.