Bought myself a handful of Cokin (P) filters last year, along with the holder and respective step rings for my lenses. I've found the whole system a bit of a pain to use quickly, especially after getting a screw in 10 stop filter last month which is a breeze to use. Got me thinking about what others used... Yes, the Cokin system is cheap, I can use any filter on any lens, but what use is a flexible system if you don't actually use it ?
I'm now considering getting a handful of ND/GND screw in filters to join my 10 stop specifically for my current most used "landscape" lens, the 72mm 15-85mm EF-S. I'm unlikely to be buying loads of lenses in the future, there is a slim likelihood of getting a 77mm 70-200mm (f2.

at some point, but then I'm not adversed to buying the odd ND specifically for that.
I'm typically using the 0.9 ND or 0.6 GND, 95% of the time I'm using filters, and hardly use the polarising filter.
So, what do others do, use, are screw in GND's a pain, thoughts please ?