In the early 90s, I had a fairly popular DOS command line utility. When OS/2 2.0 came out with all of its 32 bit goodness, I decided to port my utility to run in the OS/2 shell. Everyone was excited to see the speed increase all those extra bits would give it. It turned out to be quite a bit slower. The ability to address more memory and move things around faster simply didn't compensate for the load that bigger, more complicated application layers and multitasking brought. 16 bit DOS was simple, straightforward and quite fast.