Well most importantly the tyres were definitely different seeing as though Robert set his fastesrt times on the ultra-softs, which weren't used during the GP weekend, nor were they used by any other driver in action today.
But the fact remains he'd never driven a 2017 car before so it was still an impressive day by him, irrespective of track conditions or tyres used. Going after the last few tenths however is gonna be a different kettle of fish so we can only hope he does get the opportunity to have a go at it at some point in the future...