I bought this set at the 2006 Canoecopia in Madison, WI and have been using it since about last March. I've only had it off the rack a few times since then.
The rubber padded gunwale brackets work great for holding the canoe in place and completely eliminated side to side slippage as well as forward or backward slippage on the rack load bars. These brackets made loading and hauling the canoes much more safe, secure and easy than my previous self made brackets. The brackets can be easily installed or uninstalled while the rack load bars are still on the car.
The brackets also work great as load stops for lumbar and other similar items on the Thule load bars.
The brackets also work great for transporting large cockpit kayaks, such as the Phoenix Poke Boat, upside down on sedans like my 97 Bonneville by placing the brackets up against the cockpit coaming just as with the gunwales on canoes.
The brackets also work well for transporting sea kayaks, such as my Aquaterra Sea Lion, right side up by placing the brackets on either side of those common shallow v shaped foam kayak carrying roof top blocks when the blocks are on the Thule load bars. Before I had the canoe brackets, the foam blocks tended to slip sideways on the load bars a little. No slipping now.
The 15' load straps that come with the 579 XT are the best load straps I've used in respect to their ability to retain constant tension regardless of changes in wetness or temperature. Unlike many straps I've used, the Thule straps don't lengthen when getting wet or cooling down and don't tighten when drying out or getting warmer. These are very nice characteristics when transporting the boat through changing temperatures or alternating wet and dry conditions. I no longer have to stop and tighten my straps when I drive through a rain shower - that was a hassle. I only wish that they came in some other sizes than 15', such as 12' and 9'.
As for the Quick Draw bown and stern tie downs, I haven't actually put them to the test because I'm satisfied with the other load straps that I've been using for the bow and stern tie downs. I may experiment a little more with them next season. Also, initial set up of these tie downs requires tying the nylon line on to the steel S hooks and I don't tie good nots yet.
All in all, I highly recommend these brackets for folks who transport their canoes or large cockpit kayaks on Thule load bars as well as those that use the v shaped foam kayak carriers on Thule load bars.