Well, looking more at the manuals, comparing the Carezza manual and the Baby Class manual, I'm surprised at how similar the two are. I didn't compare word-for-word, but most of the manuals look/read exactly the same. For example, the pages even line up. I.E. page 15 of the Baby Class manual looks exactly the same as page 15 of the Carezza manual. I guess what I'm saying is that I suspect that Gaggia tried to re-use the text of one manual as much as they could.
One note: the Baby Class manual doesn't even mention anything about a 3-way valve. At least I couldn't find anything using the search function of my PDF reader. I tried searching quite a few things, like three-way, 3-way, 3, 3 way, valve, solenoid, etc..., and nothing showed up.
Also, about the "PF sneeze," both manuals say:
Gaggia manual, p. 15 wrote:To make more espresso, carefully and slowly remove the filter holder by moving handle to the left. Be careful as hot water will be on top of the coffee grinds in the holder. Some water will continue to drip from brewing head as filter holder is removed. That is normal and due to the pump pressure in the system.
Here's links, if anyone else wants to compare the manuals.
Carezza manualBaby Class manual