As a related issue, when considering the PID upgrade, I also decided to switch to a 4 hole tip. They were back ordered, and the vendor suggested another brand tip that they said would fit.
After install of the PID and new tip, I was very disappointed with the steam performance. If anything, it seemed like there was less steam than before, it certain didn't froth a pitcher of milk any faster. I used it for about a month and noticed I had a lot more difficulty cleaning milk off the tip after steaming. When I realized the end of the tip was brown from burned milk, I removed the tip.
The new tip had no recess inside for the non-burn tube. When I put on the new 4 hole tip, it had crushed and distorted the tube, partially blocking any flow. I straightened the tube as best I could and re-installed the original tip. What a difference. The amount of steam was now incredible. Milk steamed in 1/4 the time.
If considering a 4 hole tip, I recommend staying with the original brand if you intend to leave the no-burn tube in place.
After I got the PID, kinked tube (my fault) and the tip straightened out, yes I would recommend the upgrade. My temp increased to 272 and pressure up about 1 bar, (if I remember correctly, not at home relight now). The initial steam blast when cleaning any condensate is scary compared to original.
I steam two pitchers of milk, 17 Oz. each, for our two morning 2 double shot lattes. Steaming used to take a lot of time. I haven't timed steaming, but initial frothing to 100 degrees is very fast, the hand on the thermometer moves like a second hand. At that point, I submerge the tip and grind18 gram into a basket. With my grinder, that's less than 3 seconds. Quick weigh, and I have to shut off the steam as the milk has reached my desired 170 degrees. If really on my game, I might get the PF tamped before I have to stop steaming.
Between the PID upgrade and new grinder I've cut morning prep time in half. Including clean up and dishes from 30 to 15 minutes.
PS: PID makes no difference on brew temp. You still set that the same as before. It allows you to set the steam temperature up from about 250 to 270. This results in a higher pressure hence the pressure relief valve that also must be installed.
The higher steam volume and heat is more quickly transferred to the milk, significantly reducing the frothing time. The higher pressure also greatly increases the rolling and turbulence of the milk in the picture, providing better incorporation and finer micro foam.
I'd say the upgrade brings the steaming up to the level of the rest of the machines feature and feel it was a very worthwhile upgrade. It's standard on current machines. Ordered mine 3 months too early, but I think they raised the price on the new machine, so I'm even I guess.