Diamond Jubilee, hands down with HEPA bag and the Aerus cabon filter after that. But partially because I bought one new on our first farm from an Elux salesperson.
I don't have any allergies though and using a Connie on hardwood floors blows allergians everywhere.....sooooo, I pretty much go for the 'expereince' of vacuuming.
I recognize that the Super J, Oly One and Silverado all use the the bigger motor the Super J model ushered in. I have about 5 Super J's waiting to be restored. If I find a nice Silverado or Oly One, I'll pick up one of those too.
However, when I get serious about cleaning because company is coming...roll out the Diamond J.
Kevin