I've been happy with my B+W polarizers. Got a 72mm MRC and a 77mm MRC Kasemann a few years ago.
The only thing I have bad to say about B+W is to never buy any of their slim filters that require the push-on cap. That thing is worse than worthless, and falls off constantly. I know 2 people who bought thin B+W polarizers with the push on caps and both had this problem.
I hear they have made new thin filters with a small front thread though, so you can continue to use a standard pinch-on cap. I would go for this, and will probably upgrade to something like this eventually.
I'm always the opposite and like using my CP in addition to a ND filter for helping increase my exposure times lol
I guess I could see the advantage of less light loss for blowing vegetation etc, but given I usually only use a CP for tripod work, and perhaps don't shoot under windy conditions, I've never found an issue where I said "darn, if only this CP didn't cut so much light"
Do I need to go with the Slim line in B&W MRC Kaesemann for my TSE 24, and my 16-35 Series II? Can you still use the lens hoods with the slim filters? I would prefer the regular ones over the thin, due to lens cap issues and the ability to get hold of them to unscrew them, but I have concerns about vignetting.
Both B&W and Marumi now have slim versions that also have front filter threads to allow lens cap use. Check out the fine print in the descriptions to make sure you get what you want.
I just ordered Marumi CPs for three lenses. I still need to get an ND to share, but got the Big Stopper as well, and the Lee holder. www.2filters.com Advice from FMers really lets you buy with confidence.
Well, I knew there was a 2/3's in there somewhere 
