you know what, I just tried the Cokin 'cause it was inexpensive and light weight, simple etc... just stayed with it. And I only use it for grad filters anyway; been using 'em for years now. I carry high quality glass for anything else.

Ah, practice with your Grafmatic in the light so you can make sure you are getting the septums in right. I've noted some Gramatics have a tab that needs to be pushed down when closing, but the one I use does not.
I found the key to the deal is all feel anyway, but I always open it and re-familiarize myself with it before loading and going out with it if I haven't used for while. I've loaded mine in a bag a couple times; it can be done.

I see you have a 135 Optar. Nice lens; one of my favorites. Makes a nice portrait in medium format. They can vary a bit. Play around with it wide open for a softer classic look, esspecially if it's an older production run. They do a real nice job with classic automobiles and make a nice star effect on bright chrome.