I'm not trying to be critical for no reason, nor am I trying to be a jerk. I'm just saying, from the perspective of someone who has worked in some very high-volume pizzerias and restaurants, that it looks like the PVC technique creates more work than it eliminates. Also, having spent time in some ridiculously inefficient kitchens, I've seen how just a little bit of unnecessary extra work here and there can contribute heavily to killing a pizzeria.
Earlier this year I went to California for a month to try to help a new pizzeria owner I'd met through these boards. Even though I went there primarily to help with marketing, I was blown away by how inefficiently this pizzeria operated. It didn't take me long to figure out that no one in the place (including the owners) had ever worked at a remotely high-volume foodservice establishment. Consequently, no one in the place had a clue how to handle even a minor peak in demand.
Due largely to its awesome location, this pizzeria should have been able to attract a ton of customers without spending a dime on marketing. With many large office buildings in the immediate vicinity, the pizzeria had lots of first-time customers almost every day at lunchtime, as well as plenty of instantly-lost almost-first-time customers at all hours. What I mean by "instantly-lost almost-first-time customers" is that people would walk in and walk right back out after looking for 10 or 20 seconds at the attractive-but-cluttered menu boards that were difficult to decipher. This was at least partly due to the extensive list of "specialty" pies junking up the menu, many of which had no logical combination of toppings.
But to get back on topic: Whenever there was any business, the kitchen couldn't keep up with demand. Almost everything was done as inefficiently as possible, which means workers had to do considerably more work than should have been necessary to get the job done. And the smallest hint of inefficiency is almost always the beginning of a big-time snowball effect.
For slices, they offered what I've seen referred to as a "poor man's slice." That is, they kept several nearly-fully-baked cheese pizzas on a rack beside the make table, and people could order slices with any combination of toppings added to a cheese slice. Whenever someone ordered a slice, a ticket would print at the make table and eventually the toppings would be added to a cheese slice, but not until the "chef" actually read the ticket, which usually didn't happen for at least five or ten minutes after the order was taken. The slice would then spend probably five minutes in the oven, which I think was kept at 500. Finally, the "chef" would put the slice on a plate and set it in the window between the kitchen and dining area, which means it would probably be another few minutes before the customer got his or her hands on the slice.
All this did was negate the convenience factor of offering slices because it takes almost as much time to go through this process as it does to just make a fresh pizza; and that's in addition to the time it took to make the pizza the first time. So essentially they'd have to make a pizza twice for every slice order. And I'm sure most people, like myself, don't want it done that way. If I order a slice with toppings, I want a slice of a pizza that was fully baked with the toppings I crave.
This was not the result of one big inefficient procedure; it was the result of the combination of several small inefficient procedures.
Compare this process to buying a slice at any slice joint in New York. In New York you walk up to the slice display and choose from about ten different slice pies. You point at the pizza you want and say, "Two of these." Then you pay. Two minutes later you have your slices and it took almost no time or effort for the pizzeria staff to take care of you. This model makes money because it's efficient and it leads to customers receiving a better product.
At the pizzeria in California, long wait times alone led to unnecessary customer dissatisfaction, which leads to a low repeat customer rate. And none of the staff, nor the ownership, had a clue that it should have been any different.
I don't expect anyone to understand the point I may have been trying to make here, but I could go on and on with countless other examples of inefficient pizzeria operations and how little inefficiencies make huge impacts on the bottom line.