Simple to use
Packs away nicely
Internals look like they could be bought at radio shack
Got my chrony F1 for $74 at a local gun shop. Don't get suckered into buying the "paintball" specific one. All that includes is a plastic splatter guard and a gun barrel rest, neither of which you need and only adds about $20 to the price. Take that $ and go buy a tripod to make mounting the chrony easy. As I stated above you can just put some clear packing tape over the open sensors to cover them from possible paintball breaks. We've broke quite a few balls over the chrony now (my buddy's full auto guns with crappy hoppers tend to chop; my Xtra never chops) and haven't had any problems.
The Chrony has a mounting hole that allows you to mount the chrony to any camera tripod. I have a cheap $20 tripod from wal-mart that works great. The chrony has worked fine for me. It measured velocity just like it was supposed to. It even worked well in the garage after we figured out that fluorescent lights screw up the sensors (the pulsing of the lights fools the sensors.) What you have to do is use the plastic outside cloud diffusers and then position a lamp with a regular incandescent bulb over the chrony. Once we did that it worked perfectly in the garage (we were shooting into a garbage can filled with cardboard to tune the guns in.
I read on a website somewhere that you can also just strip the wires on a 1/8" stereo plug and then either just touch the wires, or hook up a momentary switch and be able to cycle though the different functions of the chrony. In other words, you don't have to buy their extra button switch to access the included functions on the chrony. The extra screen functions show things like average, hi-low, etc. If you don't have the switch the chrony just displays shot # and what velocity in FPS.
Works great, folds up for easy storage, can be a little finicky but not too bad, inexpensive (relative to other chronographs). I give it a 9 just for the cosmetic cheesyness of the guts, but hey, it works as advertised.