I have only had positive reactions wearing my Rainbow dash t shirt, lots of Bro hooves, however that was mostly at comic con.
Also when I wore it to Alton Towers theme park one of the ride operator brohooved me and stopped the ride for 5 minutes (with people waiting xD) to talk ponies with me.
All that said would not wear it around my home town, where lets say people there aren’t to keen on people being different =p.