Ok, so it's been a bit but here is my review of my pen. I bought this before a 6 week underway and used it the whole time and since I've been home for about a month so I've had some pretty good experience with it.
The pen comes barebones packaged. I actually like that because I know I'm not paying for some flashy box and just for the pen. Plus, I'm sure whatever is left over goes to helping buy part of a six pack, but we all gotta make money somehow so overall, for what the pen is, the cost is pretty spot on.
First impression, this sucker is solid. It is thicker than an ink pen but it's not too thick. I have normal size hands and it isn't abnormal or difficult to hold in my hand. I do wish it would fit in my flightsuit pocket but considering I'm only going to use it in the cockpit that's not a big deal. I tried it out in various positions to compare it to Phrog's observations and I prefer to have the on/off button under my pointer finger and not my thumb. The clip rests under my finger and kinda hooks onto it and keeps it from moving. Rotating it either way is no problem. Also construction wise, the clip is beefy. Being a helo guy I didn't really want to have an idiot string on it because I'd need to point at breakers/switches so that'd be a really long string, so I just clip it onto the clip on my 9G kneeboard. This thing won't fall off and I'm not worried one bit about the clip breaking, even after using it for a long time.
First time in the helo, I had to readjust my thinking. Previously, I had a flashlight and I would just flash it at what I was looking at and not really get it close. The pen is by no means a flashlight so I can't really point and just see whatever I'm looking at. I had to hold it close to whatever switch, etc, I was looking at to read it. It wasn't and isn't a bad on the pen, it was just a different way of thinking when I need to look at something. Writing on my kneeboard is no problem, there is plenty of light to see the page. For that matter, there's no problem reading a checklist too. Now it's no brainer.
The light is definitely NVG compatible. If you look at it through the goggles you can see it's on but it doesn't bloom at all. No more worrying about flashing my copilot with my flashlight.
I did experience some fade on the brightness of the light as I got near the end of my last underway, I didn't realize it till I was holding the pen directly against the paper just to read it. That may have been a function of the batteries that came with the pen or a function of me using it on several 3 hour night bags. Either way, once I got home I put in a fresh pair of high quality Energizers and the light is really dang bright now. It's like anything that takes batteries, it always pays to have an extra set.
The pen uses the Fisher space pen refill and I have used those quite a bit from before so I know there's no problem with that.
The only bad, if it can even be considered that, is the contact inside of the pen. The refill slides through the body of the pen and on mine it bent the contact up. It wasn't a big deal, I just bent the contact back down and it works 4.0. Plus, the pen has a lifetime warranty so if it does become an issue down the road I know it'll be taken care of.
So, that's my take on the pen. I think it's a quality product and it definitely satisfies a need in the cockpit.
Would I buy it again? Of course, and I would recommend anyone who needs a light in the cockpit or who is tired of holding a flashlight to write to get one.