Zipp 404 users : few questions

Just received my 404 tubulars. Glued the tubs yesterday using Tufo tape (was easy enough).

I have bought Corima brake pads. I think I can still use my old brake pads, what is the downside of that ? If I put the Corima pads on, what would it be like when I have my training wheels on with Alum breaking surface ?

Computer magnet, My sigma sport magnet does not work on the Sapim spokes. What are you guys using ?

Thanks.

I use standard pads on my 404 and they work great.

A magnet is a magnet. Find one that attaches to your wheel and it will run your computer.