You broke the code. Lee filters are best at draining money from the wallets. They can be marginally useful for photography.
I don't have Lee polarizer I've couple of ND and NDG and big stopper. I hear problems with lee polarizer for wide angle even there new one specifically made for wide angle and extra 100$ (costs 300 something), I've Heliopan polarizer, but beside the polarizer I think Lee is really good quality filters, the reason i got it in the first place is that i can't make much sense from screw on graduated ND without giving me the freedom of moving it up or down. i didn't see any scientific comparison between lee filters and other manufactures but they go for a great deal in these hand made filters. it seems however that all the other guys replied (most of them anyway) favor the screw on filters.
also having one set of filters and changing only the filter adapter to use them with different lenses seemed reasonable idea to me at that time