I took the plunge on Kraftmaid during a Home Depot sale. They’ve only been installed a week, but they look great and seem like quality cabinets.

KM has several lines. I'd bet that that is the lower specified line with an Evercore door. That's the only way to get it that much cheaper than Diamond. What is the box construction and corner braces? It can still create a beautiful kitchen in the hands of a skilled designer. The big risk is that box stores rarely have skilled designers. You may want to hire a KD separately to do the design, and just give that to the store designer. There are a lot of ways to get it wrong. Every time I think I've seen it all, someone creates a better mess up!

Here's a kitchen that I did in the lower spec'd line.

mlb418, what style and stain/paint did you go with?

I got the Thornton shaker door on maple. I upgraded to plywood. The base cabinets are greyloft and the uppers are moonshine. Here’s an in progress picture. We are waiting on a couple of upper cabinets to arrive.

Thank you @ The Cook's Kitchen

Here are the layouts https://www.houzz.com/discussions/5756283/kitchen-layout-ideas-improvement-suggestions

The doors Fox Ridge Maple Square. The estimate has option APC All Plywood Construction / Natural Interior; DWM - Dove White Maple. Price reflects today's -25% discount

We were told to support a heavy quartz we should consider ply upgrade. Another question about a width of the island, we can do anywhere between 36" to 60". What would you recommend.?

That’s BS. Furniture board supports stone just fine. If the rest of the island is designed correctly. But at 12’, it isn’t.

What is so wrong with ~12', yes it will have to have a seam.