My rear struts were leaking in my 07 EL around 90k. They were replaced with some unknown brand at a chain repair shop and I thought the ride was *worse* in that the leaky ones had better control than the new ones (much to my dismay).
Now at about 130k I've installed the loaded Rancho leveling kit and replaced the original fronts and the replacement rears. These struts have fantastic control and give about 1-2 inches of lift. The only downside that I have found is that you have to crawl under the truck to make any adjustments unless you spend another $500 or so for the in-cab controller. The struts aren't cheap since they are loaded with springs and adjustable struts, so there are definitely less expensive ways to go, depending upon what you want to achieve.
I owe the forum some photos of the before an after install, but so far I've been very happy with the Ranchos.