I bought a pair of StrongArm 4361 lifts from MrLousStuff (ebay) in May of 2014 They've been "sinking" for about the last month or so, and just replaced them today with another, actually cheaper, brand from Amazon with non-detachable ball joints. The StrongArms didn't quite last 4 years. I decided not to take them up on their "limited lifetime warranty" because they want $9.88 plus my cost to pack & ship back the old pair. That's almost equal to the cost of my new replacements. Hopefully, these last a bit longer. So far, so good--very strong lift.
I also replaced the rear window lift gate pair with StrongArms around the same time as the hood lifts. The rear set still works, but can only open up to about 80%, then I have to push the gate up the rest of the way and hold it there if I need it all the way up. Not a big deal. Yet. I guess I'll give the new ones a chance to prove themselves before jumping in on getting a new set of the cheapies for the back.