The problems are mostly not about GPU power, but awful CPU performance it seems.

I’m aware, however it’s not as transparent and Steam does not provide the same guarantees that GOG do.

Better than Steam I’d argue. Unlike Steam, games you buy on GOG are yours to keep forever. No DRM like steam that forces you to log on after a few days offline. You also get better version control.

Edit: the offline limit was a bug. Offline restrictions would be dependent on the DRM solution for each individual game.