The fact is the normal view used to be very fast even on the hardware of the era. Nowadays normal view has the same functionalities but is much slower even on modern hardware.
My gmail was great on my commodity 2010 Windows laptop until a couple of months ago, and then it suddenly fell off a cliff. I've tried everything I can think of, but I think Google just messed something up and made it at least an order of magnitude slower quite recently.
I used basic view for a while, and didn't miss any of the advanced features. What made me stop was the fact it inserts newlines into messages to keep lines below 70 characters. (I guess this is in line with the RFC, but my recipients didn't like it.)
