So I've heard tell of high level play making use of Taric. Is there anything in particular that makes him good? How do you build him? Could he pull off solo queue or is he only good under strict cooperation?

I can see his armor buff being fantastic because Dominion tends to run AD heavy, but he seems slow, healing in dominion in general is pretty "meh".

Or did I hear wrong, and is Taric not even being used?

I am nowhere near high level, but spirit visage + frozen heart makes him pretty tanky, and if you have a carry who will take advantage of your stuns and auras, it seems to be effective at my ELO.

The most successful ones I've seen have built tanky ad. Not sure what items, but prob a combo of fratmas, frozen heart, maybe zeke's.

I played him once in an ARAB (all random all bottom) game and once in a random select where I was Taric. I got nashors, some MR and Armor, cant remember from there, in the ARAB game my last item was a phantom dancer for laughs. I almost carried the team as I could heal myself every 4 seconds while attacking champions I won the game for us but I wasnt the bursty damage of our carry but Id win any 1v1 fight it was comedic.

I like playing him quite a lot, but havnt been
super successful. I usually go support or AP, had a couple horrible games as an AD. Went total aura tanky taric in an ARAB and did great, something like 20 kills and 74 assists.

When Stark's Fervor was still around, I used to love running him with that + Black Cleaver and standard supporty aura items like Aegis. 95 total flat armor reduction on whoever you're attacking was pretty significant, and you could 1v1 a lot of AD champs in a straight up fight with ease due to all the free armor and the massive sustained heal spamming you were capable of with the attack speed. Nowadays, I guess Zeke's could still stand in for Stark's.

Try building Rodma's. Too strong.

I go AP on him when/if I random him. It's surprisingly strong. Glass cannon, but even so it can pretty much drop someone in his full combo.

I love aura taric that build tanky

Things like aegis, Solari emblem, WoTa and Abyssal scepter are fabulous on him