Control arms
If you are thinking about control arms for your Volvo, I have got two words for you: Lemforder and Febi suspension parts (German Made). For example, if you look at Lemforder bushings side-by-side with the cheaper aftermarket ones made in China, you can see a noticeable and dramatic difference. The rubber in the cheaper parts is thin and flimsy looking. The Lemforder is thick and muscular looking, like rubber on steroids. There is a big difference, even to the naked eye.
Here is bottom line folks: If you can easily do this job yourself and you don't mind changing the control arms out once a year, then go ahead and buy the cheap Chinese aftermarket parts. But if you are paying someone to do this job, then go with better parts otherwise you will be wasting a lot of money on labor cost to have it redone. Also, if you pay a shop to do the job for you, make sure you get at least a two year warranty (in writing) on the job.
The suspension is a complete system, therefore there may be other issues as well causing you problems. Just as there are many links on a chain, there are many links in a suspension and one weak link may affect the the whole system. Get everything checked out.
Update: I contacted deutschepartsusa about the failed Hamburg Technic Control Arms and they sent me some new bushings for the control arms only. Now the rubber on all the other parts in the suspension kit are failing. Don't buy this kit.