In my experience, Hitachi is the only HD manufacturer that won't do advance replacement. But I don't buy many Hitachis. I use mostly WD and Seagate. At any given time, I usually have multiple drives in the replacement pipeline, so if a customer has a bad drive, I normally replace it with one from a previous RMA and put his replacement into the pool. And yes, it's a sad comment on HD reliability.
Motherboards are a different story. There are too many platforms and particular customer preferences to have a suitable replacement on hand everytime. Most folks with a bad HD just want a replacement with similar capacity, performance, and the balance of their original warranty.
With MOBOs, you get into issues like support for support for specific CPUs, memory, bells and whistles, etc. With any mainboard, you can usually return it to the wholesaler during a specific DOA period, but outside of that, you are at the manufacturer's mercy.
I think any vendor that places a higher priority on their internal costs vs. prompt replacement is cutting their own throat in the long run. Top MOBO producers like Asus, MSI, Intel, etc will never compete with sleezy brands on price alone. They have got to offer better service. In any market, that only leads to increased profitabillity.
