I use openID to comment too, but I have it set to always remember me on my computer, so commenting here with openID is, to me, no less complicated than commenting on an LJ. And done this way, I never actually have to put in a CAPTCHA. To be honest, I never even really notice when I've ended up on dreamwidth because the process is so streamlined. Is it possible for you to set it to always remember you as well, or is that not an option given whatever your computer situation is?