I started my 'new' job at VIE some months ago (in the operations department) and when I was told that wearing a uniform is standard in this department I was quite annoyed.
After some weeks I discovered that this is a good idea when you are a lot on the apron - so you are identified as one who is allowed to be in this area even before people can read your ID.
But I consider it absolutely useless for controllers to dress in a special way for normal duty - for special events like press conferences maybe, but why in the TWR / ARTCC?
Just dress in a manner you feel good in ...
Regards, Bernhard