In addition to getting better brew temperature control, I wanted to have better steam temperature control than the standard Silvia offers. This controller does the job. It also comes with a "pre-infusion" option, which is maligned or desired, depending on your preference.
The Auber kit is meant for installation between the group head and the steam wand, so comes with an aluminum "project box" with double stick tape. I wanted a cleaner installation so decided to go internal. I was concerned about exceeding the operating temperature range of the PID so I planned the installation around the inclusion of the project box to provide a degree of thermal protection.
Auber's kit includes detailed disassembly instructions for Silvia and installation instructions for the PID, along with detailed color photos of both. If you follow them you will not have any difficulty. I followed them to a "T" and Silvia fired up perfectly at the end of the installation. I would highly recommend Auber's kit for anyone else interested in this sort of thing.
I will add a minor caveat here: I am not a shill for Auber. I paid for my kit just like anyone else, and they aren't giving me anything to include their name here. I looked at several different companies that offer PID kits, and depending on your needs any one of them will work well for you. Because of this abundance of great products, I had a hard time deciding on which one would work best for me, but I ultimately assessed that this one most closely matched my needs/wants, so it's the one I went with. Here's a link to some other kits I considered: pidkits.com/. Look around, you're sure to find some neat mounting options.
Step 1: Trace and Cut
Then I traced the outline of the project box front face's center cutout onto the front of Silvia.
3/32 holes drilled at each corner of the cutout tracing, then off to the races with my Dremel and a reinforced cutoff wheel.
I put a cloth inside to catch the brunt of the steel shavings, and covered the face of the machine as well.
Cut the rectangular hole a little small and use a flat file to open the hole up to fit the Auber PID.
Step 2: Install the Project Box
These pictures show the project box in position, as seen from the front, top, and back.
Step 3: Finishing
Thread all the wires through the back of the project box, and attach the leads to the back of the PID (again, according to Auber's excellent instructions).
Gently pull the excess wire back through the hole on the back of the project box as you guide the PID into the hole you cut out for it.
Use the zip ties in the Auber kit to secure the new wires away from Silvia's hot internal parts.
Step 4: Enjoy!
The numbers are very easy to read, and there is no question about the boiler temperature any more.
As a side note, I'm contemplating adding some vent holes above and below the PID face in order to ensure some airflow and reduce the possibility of overheating. That would likely show up as a series of 1/16" holes parallel to the top and bottom edges of the PID.