Hey man, I don't have an answer for you but I wanna bump the thread to see if you can get a response. If I had to guess, I would say the driving experience would allow you to tell if the job was done correctly or if the setup is still in good condition. Just listen and feel for things that feel a little off, if you have had experience with suspension setups in the past you will know if its a quality job or not.

As for the visual inspection, I guess just look for anything that looks out of place. I hate to give such a bad answer, but I just got out of college and have never had the money to play with suspension, and hell don't have the money now.....so my experience is very limited. I know this doesn't help much but it puts the thread at the top again!