I believe using the word “regarding” instead of the phrase “in regards to” is infinitely superior, and it annoys me to no end when the latter is used in writing or speech. Though this preference of mine may seem to be mere semantics, I posit there is in fact a relevance to their difference — for a few reasons. Before I begin I want to be very clear: this is my attempt to convince you to sympathize with my nettles purely by means of my charmingly insufferable prose, and not by anything likely worth attending to. (I am a gadfly and this is my loitering, strictly speaking.)
My first reason in favor of the superiority of “regarding” is one of practicality. It is one word, while “in regards to” is three. Additionally, there are less keyboard strokes and syllables for the former, making your writing and/or speech slightly more efficient and saving you a considerable amount of time. While I would not disdain someone for using “in regards to” to meet a word count for an abnormally-strict professor, in any other case I thoroughly maintain “regarding” is far the better practical option.
Secondly, this is an issue of grammar as well. Perhaps I am being witheringly obtuse, but I find “in regards to” to be categorically and utterly obfuscatory. What does it mean to be “in” a regard, much less plural regards? Who or what, I implore, is in those “regards”? And why do we need to say “regards to” — employing that usage we’ve not defined or understood — when the preposition “regarding” says what we mean far more implicitly and clearly? Granted, the slightly less colloquial phraseological alternative to “in regards to” — “with regard to” — is far more sensible grammatically. Yet, “regarding” indicates you’re specifying the object with a regard for its delineation. If you absolutely, needlessly must use multiple words, I beg of you to choose “with regard to” instead of “in regards to;” but I will reiterate — “regarding” is the best of them all.
Thirdly, I also think this is a debate of aesthetics, and if I am right and aesthetics have truly anything to do with this, then we have a provocatively philosophical matter on our hands. How we use words is paramount to the human experience, and certain uses of words (in this case, “regarding” and “in regards to”) we then find aesthetically thus philosophically appurtenant. How a word or phrase sounds to your listeners or readers, and to yourself as you speak it and even read it on the page, is indeed a matter of aesthetic. The words we choose indicate, on some level I’ve decided is beyond my scope, our regard for the love of wisdom. Hence, “regarding” ought to be used always in place of “in regards to,” which I find to be phonetically objectionable and melodically tedious. “Regarding,” on the other hand, has no particularly sticky consonants and features a distinctly agreeable cadence. But I have pontificated far too long; I shall abate.
I assure you that my attachment to “regarding” is entirely petty and nonserious. If someone else made this same opinion their hill to die on, they’d be mocked and run out of town, coddled by academics, or (worse) both. I’d rather avoid that demise. Perhaps, another time, I can argue our nonserious opinions actually have some significance to be acknowledged and valued. For now, though, know I genuinely and ultimately care very little, and really only enough to nurse a pet peeve and write a few hundred priggish words. If you press me on this, I shall inevitably rise up to the task of defending my opinion, but only for the sake of my pride. All the same, do remember this salient item: using one word instead of three to say the same thing is nearly always ideal. Ignore my theory if you must, but do me the honor of engaging my praxis.
Adaelle Stobie 
Miss Information 
Katherine Thomas