Szczezny world class? There must be something like 20 world class keepers in that case. I can understand the case for Koscielny but another great season perhaps would put him there. Ozil is a world class player but has had his worst season since he left his teens. Ramsey has performed at world class level but like Koscielny, I'd put him in that league if he replicates what he's done next season. If you offered me someone like Modric who's seen as world class for Ramsey, I'd tell you to go fack yourself. That's how well Ramsey has done.

Szczesny hardly makes mistakes and makes great saves but he will probably have to play at that level for another 1 or 2 seasons to get recognised.

As a confident keeper coming to get crosses and set pieces and commanding in his area, Szcez is a good keeper. That's what put him above Fabianski. As a shot-stopper, he's decent, but there are several better. I'm satisfed with Szcez but no way do I accpet he's at a rarefied level that you can call world class.
De Gea is better than Szczesny and I wouldn't call him world class at all.