i always let the vote get decided because i trust that people have gd taste in maps.
HOWEVER, when i am 100% sure that a map got fucking spam-voted, thats the only time i change the map.
mostly it would be half the server going "how the fuck did this map win the vote" when it won 80 % of votes lol...

the ONLY time i change the map from a gd map to another gd map is when i am watching a hacker, for example a waller, and i am testing his reflexes on a map decent for walls, like deagle, or lego or complex..as opposed to gg_wallhacks or some very open map

i will almost always ALWAYS change the map off of a certain rats map with the toilet chair in wcs, its the most retarded map ever.
and in gg, i have a 17-map-rotation. usually one of those maps gets picked, i leave it, but if ppl picked a crappy map like some fucked up texture map, i change it off simply bcos ppl expect it .

blah blah, the reason im saying this is because
tl/dr
so if ppl spam the map changes to their needs only ,it gets annoyin sure, but admins do reserve the right to overrule a map vote based on the current scenario.
so u cant really bitch about the "feature" but you can indeed bitch at THAT admin per say, if u show proof that he is abusing his right by constant changes (like changing the map 2-3 times in a same game etc... or changing the map halfway in the game when someone already passed level 13 in gg... shit like that...)