Hi Richard,
I tested the electro-magnets and decided to scrap them:
1. The delayed feature did not work correctly--did not separate the couplers enough.
2. They got really hot after only a few seconds--I couldn't trust them.
3. They are tedius to assemble and install.
4. They look terrible.
I agree with the above advice. Although, I went with the permanent under the table magnets by McHenry (Kadee moved the couplers too far) and have had no problems. They work correctly and I have had no false uncouplings. I operate a small shelf layout, and realize that a long fast mainline run might pose different problems.
Good luck.
Bill