I wish I could tell you that any of these meters gave solid data on noise and perception. So much depends on the filtration in your gear as well.
My basic guidelines are to create two zones of power conditioning. One is the clean zone on which your analog devices with nice power supplies run and another is the dirty zone for wall warts, TVs and PC's.
The biggest mistake I see users make is to put noisy and dirty devices on the same outputs of a power conditioner. With few exceptions you just introduce noise after it's been removed.