I haven't built any of the boards mentioned here, but I have a multiplex board on the way... or maybe in my mailbox. I didn't see it when I got home last night, but I just checked the tracking and USPS says it was delivered yesterday.

I've wanted to get my hands on this board for a while.
I hope I'm not derailing this thread too much, but I figure my question may be applicable since the Zero Point is also a PT2399 delay.
In the Multiplex instructions, it suggests trying a few PT2399s because some of them can be noisy. I haven't used these ICs before. Is there really that much variation? I have to order some, so should I put much weight in this suggestion? I plan on ordering at least a couple more than I actually need right now, but can anyone chime in on how variable these actually are?