Although other opinions oviously differ, I bought a Chrony (Beta Master), and I absolutely hated it. It has since been returned.
The unit never provided truly repeatable accuracy (a load that should have been giving around 2,600 fps would show velocities in that range for maybe 5 of 10 shots, with other shots showing wildly inaccurate readings like 3,100 fps, or 1,700 fps). Additionally, it only recorded maybe half of the shots I put over the unit. The others would give me Error1 or Error2 messages.
Plus, despite the claims that this unit would pack easily into the folding case, that really isn't the way it worked. The diffusers wouldn't fit in there, and the phone cord cable was nearly impossible to repack in that tiny case. So, even if the unit was small for storage, you still had a bunch of other parts laying around.
I'm shopping for a different brand at this point. Though I've never owned one, I've heard good things about the CED Millenium chornograph.