I've heard such mixed reviews about Dahlkemper Jewelry that I really can't make up my own mind about them.
I've had family members that have purchased some fairly expensive sets from them, only to have them fall apart and when they were returned told "Sorry, that's not our fault". While I've had other people tell me they purchased ring sets from Dahlkemper's and have not only loved the rings but had great luck as far as the stone settings and such.
My personal opinion is that they are very over priced and very full of themselves. While some of the sales people seem happy to wait on you, others sit there and look at you as if you've interrupted their dinner hour in the middle of their dining room.
I want someone who will stand behind their jewelry without hassles and offer the best product for the price. Sometimes you want to spend a little, sometimes you want to spend a lot... they should be happy to see you in either case.