The still shape is regarded as very important to the flavours produced in the end spirit. It as been reported time and time again that whenever a distillery has to get new still all the dimenssions of the old one will be taken so the new one can be replicated exactly.
It is believed that tall stills produce a finer and more delicate spirit where as smaller still give a fuller richer spirit. Many other factors also affect the sprits flavour, the angle of the lyne arm whether a purifier is in place and how the spirit is heated to name but a few.