i have 2 scythe fans and one of them is at least 2 years old. no problem so far :)
if you want reliability get some of these
NCIX.com - Buy Noctua NF-S12B FLX 120MM Ultra Quiet Cooling Fan 600-1200RPM 49.2-100.6M3/H 6.2-18.1DBA Molex - Noctua NF-S12B-FLX In Canada.
even those noctua have lower RPM and CFM, they still can kick a 100CFM fan's ass in terms of intake and exhaust/CPU fan