I can't help but feel a little guilty: after years of hoping for the PS2-era assets to be scrubbed from the PS3 games, it seems Polyphony has heard those of us that said "no last-gen assets" and took it to heart. The cruel irony being that, largely, the Premiums didn't need to be ditched, as they were, in PD's own words, "future-proof".
I'd love to know what's different about, say, the Z4 in GT Sport and the one in GT6, from a modelling perspective. They certainly don't look any different, and as pointed out earlier, the SLS has familiar modelling quirks.