@NilsLW are you speaking about the old Buzz sweatshirts or the newer style (which have probably been around for 10 years now!).
My experience is that the older style were shorter, boxier and smaller all round for that vintage style fit but in reality, sizing up is advisable. I had 2 in size M but sold them as they were a bit too small. The fabric seemed good though iirc.
I’ve had the newer style in olive in size L for about 10 years and it seems loose and shapeless, I should’ve sized down to a M. The neck v-insert is sewn on to the fabric rather than a separate piece inserted into the space and the fabric seems a bit thin and stretchy. I wouldn’t recommend them at all and I sold a red one I had.
I have a number of Deluxeware sweats, which are far superior in fabric and fit and unless these were to change, I wouldn’t buy anything else.