So I'm not super great on reviewing things but I'll put out my thoughts here. The manufacturing on these is great; clean threads, no wiggle in any of the parts, mechanizes all work smoothly. They are both tail heavy, doesn't effect writing but wont balance on your finger. Some specifics on each of the pens. The ED-01 is pretty slick, the action is a internal bolt, slide the sleeve down and twist. The grip section checkering is not at all abrasive and feels good in your hand. Couple of issues I've noticed. The sleeve for the bolt action scratches the main body, not deep but the pen looks worn after two days. The stylus is basically useless, I don't know if it's the low conductivity of the Titanium or the Tungsten breaker, but it doesn't work 99% of the time. They should have just used Brass and made the breaker an option you could change out. It just looks odd with the breaker exposed and with just an open hole in the end. The ED-02 is also pretty cool, a little more polished than the ED-01. The screw action is simple and easy, can't ever break. The hex grip section isn't to my liking, nothing really wrong with it, but I find myself stopping to check that I'm holding it correct before writing anything down. That's just a personal preference so can't really say that's an issue. Only one real problem with the pen. The cap on the screw mechanism, the clean cut threads on this part are a little to sharp. If you don't stop exactly when the screw is all they way down or up, they will cut your skin, not deep enough to bleed, but you get little slices in your finger tips. Would be better to have a flush and breaker tip you could swap, in stead of reversible. Hope that's some helpful incite. If there's anything specific just ask.