I wouldn't exactly call GTA IV a "benchmark", unless you want to call it a benchmark for how NOT to port something to the PC.
I don't think he was referring to the quality of porting to PC, but rather to the game itself. Huge sandbox city and storyline was done well. Yeah the PC version could have easily been the best but it wasn't ported well. We all know that it has a lot of issues.
For me though, the MP gameplay was rather shallow. Handful of weaons, poor weapon mechanics, etc.. It was good for MP, but not fantastic. No dedicated servers, no modding, poor performance, etc..
Perpetual debt is slavery.