I have a Lee Filter Kit that I use with my Canon 17-55 on a 60D.

after using standard ND and Grad ND filters...I am looking at getting a Circular Polariser.

Lee Filters make a 105mm CPL for outdoor use that attaches onto their existing holder with a adapter. This setup costs around $350 (B&H).

One Benefit of the Lee system is I can put up to 2 more filters along with the CPL. (I don't know if this is ever required)

I can get a B+W 77mm Circular Polarizer MRC Filter for around $110 (B&H).

Is the Lee CPL any better than the B+W. Even if I buy 2 B+W (72mm and 77mm which covers almost all canon lenses) it is still cheaper.

Any insight on this matter would be great.

Thanks