What the hell? Most of that info is false. For Inno3D, Palit, Gainward, the warranty is dealt with by the whoever you bought the card off. And if you really have dealt with all these manufacturers directly you would know that Asus and MSI are the two worst. Palit and Gainward are easy to deal with, the only problem is Palit's RMA to Hong Kong. Gainward is in Germany. Gigabyte and EVGA are probably the two quickest and best companies if you have to return a card directly. Zotac has the longest Warranty and one of the quickest turn around times but people would still buy Asus and MSI over one. Despite Asus and MSI having much worse customer support.
The only thing you have right is the length of Warranty.
You send your card to the retailer yes, who then send it on to the manufacturer. Asus, Gigabyte, EVGA I've returned stuff through and always gotten a replacement within 28 days and sometimes a slight upgrade in the process. Pallit and Inno3d I've returned stuff, gone over the 28 days, tried to get a resolution from the retailer and been offered peanuts and had to go through CC company. Not all GPU's but I can't see how Asus' monitor warranty process would be drastically different to GPU for example.
I've not used MSI's RMA process but I have had a number of MSI cards and not had any problems with them.
For me, I'm simply not going to buy a £1100 GPU with a 2 year warranty, when for the same price I can get a 4 year warranty from another brand. If there are any problems then I can fall back on a credit card claim, but having 4 years to do that instead of 2 is a big plus imo, and pallit and inno definitely have worse resale value when you tell people its out of warranty vs having 2 years left.