Still deciding between a 2019 21.5" and 27" iMac. I'd like a decent graphics card for future proofing so if I go with the 21.5", I'll probably upgrade to the Vega 20. I know the Vega 20 is better than the 560X, but I don't know how it compares with the GPU options (570/575/580X) on the 27" iMac's. Is it on the same level?