Others say...

"Be sure of what you have..."
I'm really really upset at this purchase. The unit itself is fine, I like the design, weight and feel. BUT not with all Kensington tips. I have a Dell laptop that uses an N19 tip. Guess what? It doesn't fit. There is an extra grove in that tip that prevents it from attaching properly.

Kensington should notify customers about this.

I followed up with Kensington directly. Their response is, "Thank you for contacting Kensington Technical Support. I understand your concern.
I am sorry for the inconvenience caused. However, we will forward your case to our porduct Design Team. I sincerely apologize for the inconvenience caused.

In the meantime, I've trashed the packinging and ditched the receipt, can't even send it back to Amazon... Wait, I know, I'll buy a new laptop with a power supply that fits! :/

"Compact, but a little heavy"
It looks like Kensington put a lot of thought into this product, which is good to see. The cable itself is a flat ribbon cable (to facilitate winding), and of the 5 conductors in the cable, the two that carry the most current are wider than the others (lower resistance, less wasted power, and less likely to fail). The winder folds over so that the knob doesn't protrude and get snagged on things. The winder also has a ratcheting mechanism (don't worry, it doesn't click) so that you can't accidentally "unwind". I'm sure this is done to save the cable from getting loose inside the winder and causing problems. I'm sure most of you have experienced this problem with long, hand wound tape measures.

The cable with the winder is a few feet shorter than the standard cable that comes with the Kensington system, but the winder is very nice. It is much easier to wind up the cable than to have to fold up and wrap the standard cable. I'm glad Kensington went with a shorter cable length on this product. I've never had to use all 10' of the standard cable.

The winder looks and feels well-built, but I wouldn't abuse it. The winder also adds a little weight. As a result, this winding cable is heavier than the longer cable included with the charger. If weight is your primary concern, stick with the cable your system came with. I bought this because it's more compact and easier to manage, so I'm happy with my purchase. I don't mind hauling another ounce or two, given that I'm already saving so much weight by carrying one charger instead of 4.

"Missing a catch"
As others have said the reel has no catch to hold it in any wind position. The ends stick in the reel only slightly when full wound. If you hold the reel by a connector the reel will always drop to the floor unwinding. There is no resistance on the spool. This causes two problems. It partially unwinds when packed and the reel drops to the floor when you are holding the connectors to insert them in your PC and wall jack. The reel is also much heavier than a similar length of CAT5 cable.

The handle folds and would appear to lock the reel but it does not. As the handle folds it completely disengages from the reel. I can think of several ways Kensington could have solved these problem, like adding a little friction or a spring to the reel, adding a clamp on one or both cable guides, shaping the guides to hold the ends snuggly when fully retracted, etc.

It is also surprisingly difficult to hold when winding. The cable spools up higher on the open edges of the reel than the side panels so you can't hold it the normal way. The crank runs very close to one side panel or it disengages from the reel, so you have to hold it by the opposite side panel. The one edge you can hold is thin and slippery.

Pretty much a terrible all around design.

"Great"
This saves a LOT of hassle on the go...easy and quick to pack. Works great and is light. Measures about 3 inches across. The reel does not lock however (contrary to the previous review) so if it dangles off the edge of a table the whole cable unreels, but this is still a great on-the-go cable.

"Nice idea, poorly executed"
This cable winder is one of the main reason I went with the Kensington adapter. It's a great idea, but unfortunately it is made so cheaply that after less than a couple of months it just doesn't work anymore as the mechanism that winds the cable back is shot.