CFM is important, but if you are mounting them to a rad, you should be looking at static pressure (i.e. the ability of the fan to push air through an obstruction)
Here is a chart for the Gentle Typhoon
http://img.techpowerup.org/100421/37005551.jpg
Who cares if the fan pushes 80CFM if it cant get it through the rad and blows it off through the sides? When 58CFM with 80% of the air going through your rad vents will cool that puppy real nice. Less CFM through the fan, but more CFM through the rad.
Edit: I can't find ratings of the Static Pressure rating of the XLF-F1254, but they are rated for 61 CFM as opposed to the 58CFM of the Gentle Typhoon. So it is 3CFM more than the Gentle Typhoon, but most reviews show the Static Pressure of the Gentle Typhoon to be one of the best out there. (Gelid also makes an awesome one.)