2 thoughts:
would be awesome if you could fade the sprites according to the camera angle, atm i keep my self asking where the flares've gone after they left the picture borders.
is the sunsprite included as well? your lensflares look a little too "round" and too "sharp". i remember the flares in ss2 for example,

http://www.3dchips.net/test/hard/grafik/truform/TI500SeriousSam2c.jpg
http://www.ixbt.com/video2/images/tech_ss2/ss2_flare_2.jpg

furthermore, i'd love to have more "sprites in sprites", atm it looks like they were aligned on an invisible wire. sorry for beefing your work, but to be honest, atm it's just one of many lensflares, not the top behrenberg quality i'm used to see