Power conditioner -- when to replace?

I just bought a Furman power conditioner for my bedroom system to manage all my cords.  While investigating power conditioners, I came up on a couple of sites that suggested that they lose their effectiveness after as little as two years.  I have a beefy PowerVar 12 Power Conditioner that I have had in my main system  for maybe 10 years and I got to thinking that it might be at the end of its life.  

I welcome any thoughts on this longevity issue.  Thanks.