Summary: Summary: If you plan to use this on a desktop environment it's top notch, I would certainly recommend it. If you plan to use it on the couch, in bed, on your lap I would have to recommend that you look at other units.(Grain of salt: I am a hardware/software tester by occupation so i'm very critical, and I'm also using this device slightly differently than it's designed purpose)
Weaknesses-For this purpose it's almost unsuited as the fans blow out the bottom and are blocked by setting them on a cushion or pants. The power cord comes out of the side so it might get in the way more than if it was in the back. The pass-through usb power cable, although a good idea if you are limited on usb ports is far too bulky if you have usb ports on the side.
Strengths-The unit is very light and relatively quiet. If you don't have enough usb ports then this one doesn't prevent you from using the one it's plugged into.
I typically use my laptop in bed, on the couch, on my lap etc.. so I purchased a cooler to keep the fire out of my lap and cool off my desktop replacement. In this environment it has several critical flaws: 1.The unit blows out the bottom with no second layer so soft surfaces render it into a block of plastic. 2.The usb pass-through is bulky enough for you to worry about breaking it off. 3.It has no provision for attaching to your laptop in any way, so you now have two things on your lap connected by a power cable. The three things that would solve this unit's issues and still make it well suited for a desktop would be 1. a false bottom so they fans exhaust to the sides of the unit, 2. a right angle usb cord, perhaps even one that swivels, and 3. attachments for the desktop, perhaps just sticky velcro. That being said I like the unit enough that I'll probably mod it myself and make a power cord.
-There's my $.02

Summary: My laptop is a new one so it never has any problem. But I noticed that when I used this cooler my laptop fan seldom starts. I really like it. The only thing I am dissatisfied with is the fans are too loud.

Update: Power connector on unit sticks out too much, jack is not working now. Too bad.

Summary: the first unit purchased shorted out at the USB connection
after 20 days. Purchased at BJ's promtly exchanched no questions asked. Second unit lasted 5 days again the connection wire failed. connected transformer to unit and it ran very well. returned for refund no questions asked, while at return counter noticed two other units also returned. cooler is only powered from ac running through USB jack and obviously would still be in use if a transformer were used instead of poorly made cheap USB wiring.