*Sorry, I read the topic wrong and below experience is for Irvine Pacific Design Center.
Not only do they charge a premium for labor and material, but everything you spend there will also be counted towards your final home price, which means you will be paying property tax for your upgrades. That said, some things you will still want to get from them:
To get:
Low voltage/Electricals
Kitchen/bath cabinet upgrades
To consider:
Countertops - They charge a huge premium of course, but since they give you credit for the standard that you're replacing, it might turn out to be close to what you can find outside. It will also depend on your measurements since you have to buy it by the slab outside.
Sinks - If you get the countertops from them then you will also have to do the sinks here.
Don't do it:
Flooring - cant speak for carpets but their pricing for hardwood floor is at least 25-50% higher for the exact same thing. Their selling point is their warranty and that any flooring work done outside will void it. But with the upfront premium they charge plus the perpetual property tax, I wouldn't do it.
Appliances
The key is to just go in, utilize your designer's expertise, add everything you want to the wish list, then take that list and go shop around. I do know 2 people who got everything through the design center because they didn't have time to look around, and both are very satisfied with the service and work. However, both also admitted that they wish they had the time to shop for better deals. The people that I have came across at the design center so far are nice and easy-going, and I just keep an honest relationship with them and tell them upfront that I will be shopping around to see my options. Good luck!