It was very much quieter.
The fan/heatsink I got was one of the old 486/Pentium-I low profile jobs. It is exactly the same area as the 040, but it can't fit exactly under the keyboard, so I had to move it about 5mm. That said, it gave much better cooling and was far, far quieter than the original fan, which was this tiny, noisy little thing sat atop a small bonded heatsink.