I installed six new Milleniums in Sept 06. All pistons were within a
few grams of each other. I forget exaclty how close but closer than you
see others talking about. The weights were listed on the individual
boxes. Very smooth engine. Oil consumption now about a quart every 18
hours. If they can't deliver and you don't want to wait then go with
the ECI's. Just don't get that Continental crap.

Our experience has been similar. We installed six new Milleniums as
part of our rebuild in 2002, and have had nothing but outstanding
performance, with low oil consumption and smooth running in our
Lycoming O-540.

I don't know anything about ECIs, but can personally vouch for the
Milleniums...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"