George,
I've had mine for almost a year, and it works just fine. The printer is even more handy than I expected, and all I do is note the load and firearm data on the tape, after printing the shot string data.
All chronos I've seen in operation, appear to be sensitive to certain lighting conditions. I've observed that mine does not like bright scattered clouds, or direct sun light.
A friend recommended that I carry a 22 pistol with known ammo, to check the chrono before I start recording data. Not a bad idea, and most people have a 22 or other small pistol, that can be used for this. Often, I just fire a load I've previously run through the chrono, as a proof check, and that works well.
Doskocil makes a 26" X 13" X 6" plastic gun case, that is perfect for storing and carrying the Pact Chrono in one package. Just a little foam cutting, and you have a custom fit. There is even room for an extra diffuser arm which most people end up putting a bullet through eventually. I carry two spares!
You will need a tripod, if you don't already have one. I got a medium priced model from Ritz Camera, but they are sold everywhere, and you should be able to get one for around $50.
Bill