My biggest gripe with .5/.5 or any other blind structure where the small and big are the same is that there is very little difference between 1st and 2nd position except who goes when. Blinds being equal, you have zero incentive to fold a hand from the small unless there is a raise. That’s good for action, suck outs, bad beats etc, but I prefer more decision making and strategy whenever possible. There isn’t a lot that you can do about it at smaller stakes, but it’s hard enough to get people to drop a hand for just a few dollars/cents. Giving 2 people an auto free look in a passive game/hand doesn’t sit well with me.
Smaller potatoes, but I find it harder to remember who’s small and big when folks aren’t paying attention and someone forgets to move the button. Keeping the blinds different usually makes it easier to recall who put out the one chip and who put out the two chips in the previous hand.
From a dollars and cents stand point, there isn’t much of a difference. I play a .25/.5 game that runs way more like a .5/1 game.
It’s not an issue of right or wrong. Just a strong personal preference.