Yeah, I was mostly kidding about Coric - and agree he is more formidable than Polansky. Coric has been stagnant for about two years now, with little to no sign of improvement. That said, I do think he'll take a step forward at some point, but will probably be no better than something like David Goffin. I suppose there's a slim chance that, in a best-case scenario, he turns into David Ferrer. Nothing to be ashamed of. But I still see a #15-30 type as being more likely.
Well said on Thiem. When I've seen him play, he looks like he still has another level he can reach, if he's more consistent. But given that he's almost 24, I'm not sure this is going to change.