For those who are curious how the story ends: Counters are in! They were added two days ago, and faucets / plumbing connections went in yesterday. We stayed with the fabricators with whom Ikea set us up. I think things worked out fairly well. It's really hard to see other people's seams online and I've never had a stone counter before, so I don't know how ours compares. I think we're probably more or less industry standard, and least so far as width goes. I can definitely see the seam (although its visiblity is affected a lot by light shifting). But it's not too bothersome. It feels smooth, which is good since I like touching the counter. :) Overall, we love how things look with the counters in. We're happy with the quartz "look".

HU: HD contracts with different fabricators all across the country. They like to award all the work in a particular state to a single fabricator.

If you've not yet paid, don't -- demand it be fixed to your satisfaction. Put your complaint in writing to the person billing you for this, send it via tracked certified mail, return receipt requested -- and do keep a copy of it. If it is not resolved to your satisfaction in a timely way, you could contact the BBB, sending them copies of that correspondence with pictures and any information about the reply. Contacting the BBB might not get you any resolution to your issues, but forewarning someone else could give you some satisfaction. If the contractor is especially obnoxious and unprofessional and unconcerned, you might find out if some local radio and/or tv stations do stories on how bad a local consumer has been treated. Well deserved bad publicity has the potential to lose them more money than it would have cost them to resolve your issues.

It's better if you find a smaller fabricator with proper licenses and insurance. Don't go with big box stores but also make sure not to do business with contractors or freelancer shops who cut quartz in their driveway, yard or a garage. Check the reviews, ask to see some of the work they already did, and that should be enough to make you certain that you're doing the job with the real professionals. And now you can say that you can be certain how a seam should not look like.