ECI vs. Millenium vs. Continental cylinders

I've read through the archives.... but would still like to hear a few more
real world experiences before I spend $7-8K on a set of IO-520 cylinders.

Anybody out there have enough hours on an overhaul using new ECI Cermi-Nil
cylinders to write home about? How about Milleniums? I'm especially
interested in hearing how the IO-520 size ECI's are holding up.

Also... anybody else out there with IO-520/O-520 conversion had problems
with the stock 182 motor mount coming apart? How about stock O-470 with a 3
blade Hartzel Scimitar? Seen any motor mount problems?

-randy cooper