I have the Jot Touch. As far as the standard stylus aspect, it’s nice. I don’t’ mind the plastic disc. BUT, the disc does mark some screen protectors. (I had a zagg HD something or other that the Jot didn’t scratch, but it wasn’t very clear. I put a cheap screen protector on and it has gathered a few scratches)
I can’t really speak to the pressure sensitivity because my stylus quit working after the first use. It’s apparently a very common problem and they will replace it, but I haven’t had time to mail it back. 
As a side note, I have an old compaq TC1100 tablet that I used to use like a cintiq. I haven’t messed with it in a couple years, but at the time it ran windows 7 and sketchbook acceptably and had a wacom digitizer. Not an ideal solution, but it was cheap when I bought it, and they’re probably even less now.