Last year, I installed a Silenx IXP-34-16 60x25mm fan in my SE/30. This 60mm fan is rated at 18cfm (at 2000rpm). The fan I removed from the SE/30 is an ELINA model# HDF6025L-12MB-1 (made by Inaba Denki). From what I've Googled, the ELINA is rated at 19CFM (3000rpm).
Of course, I checked the ELINA fan spec prior to ordering the Silenx 60mm. Because Silenx advertises the 60mm to be the same CFM as the ELINA but with a quieter operation, I decided that this Silenx 60mm fan would be the ideal replacement. And after buying it, I found the Silenx 60mm is very, very quiet -- almost inaudible. BUT, when comparing side by side with the ELINA, the ELINA moves (to my hand anyway) about twice as much air as the Silenx. So either the information I've googled about the ELINA being 19CFM is way off, or Silenx' claim of 18CFM is bogus.
So what I can say from this is, if you want a quiet 60mm fan that moves "a decent amount of air" then the Silenx IXP-34-16 is an excellent choice. But if you need it to move a lot of air (as much or more than a stock ELINA), you'd better select another fan brand.
All said, my SE/30 is very happy with the Silenx fan, as are my ears!