I've known a few Aloysiuses over the years (I'm Catholic, so it's to be expected). I don't really have strong feelings about it either way. Aloysius Gonzaga was a decent saint, but there are several dozen above him on my list of personal devotions. And his Italian name was Luigi, it's never been clear to me how that got such a terrible anglicisation. Obviously the literary associations aren't great and it's not a phonetic/obvious spelling. So, for all those reasons, I wouldn't choose it as a baby name myself, but I wouldn't raise an eyebrow at meeting another one.