the enermax CFM is probably more realistic then most fans that state 75 or 90 CFM, in fact I would state at those CFM the fan would sound like a hair dryer. 44CFM is the real world is more then enough for any case fan. Much like a PSU, its better to go with a fan considered to be a "quality" rather then one based on stats.
few web sites review fans but here are some of the better oneshttp://www.bit-tech.net/hardware/cooling/2009/09/28/what-s-the-best-case-fan/1http://www.kitguru.net/components/cooling/zardon/enermax-tb-silence-and-apollish-vegas-fans-review/
as you can see most CFM and DB stats are complete BS and buying a fan just because it states 75 or 90 CFM is pointless.
i actually had this CM fan in my case once, it lasted one day. It did not run at 69CFM (in the 40's most likely) and it DB was far from 19 (closer to 30db) http://www.newegg.com/Product/Product.aspx?Item=N82E16835103060
I also had this fan, at 3x the cost of the CM it gave the exact same performance in CFM (probably in the 50's but states 72) and DB (states 14dba but actually double that). http://www.microcenter.com/single_product_results.phtml?product_id=0251791
I've used antec tri-cool fans ever since.