I'm a pro cabinetmaker. It pains me. Really, really pains me to say this. But I will, because I believe in honesty (and you're not getting a quote from me...) IKEA cabinets are decent, with caveats. As for build quality, unless you're going either high end or custom spec, they're on par with the majority of other things put there that cost a lot more. IKEA has been in the engineered board game for a very long time and it shows. Their business model is one of efficient manufacturing by limiting variances. Limited colours and finishes, limited layouts and options mean they can focus on making a better product, rather than a huge range. They go with what works and stick with it. The hardware is really, really good for the price point. I'll even admit that I've used IKEA hardware in some of my builds (not a full kitchen, but some furniture) when my supplier didn't have what I needed. They also supply parts, often for free. Keep the manual and if you blow a hinge or drawer slide, customer service can likely give you a replacement on the spot. My supplier will put me through hell for warranty, IKEA has thrown me a bag of parts and said "There's probably triple what you need, but hang on to them if you need them". Probably the biggest endorsement I can give is to say that if I was doing my own kitchen and didn't want to make my stuff, it would be my first choice. The quality has improved greatly over the last couple of decades, to the point that I think it has surpassed most of the other "ready built" manufacturers. Most of the people will compare it to either full wood or custom spec cabinets ($$$$$), where that isn't their market. They make stuff for the average person who wants nice on a budget. There are a lot of overseas "wholesale outlets" out there selling solid wood for cheap...but the wood is iffy quality and prone to warping and shifting when transported, the hardware is awful and the finishes are horribly toxic. I would never, ever buy something like that from an overseas seller. Too many risks and not nearly enough quality control. More on reddit.com

I went down this rabbit hole. The main answer I was given is sheer weight which transfer the load down the wall. I used a combination of screws and toggles. I drilled holes in the rail in a number of locations as the holes didn't line up with the stud. Another area we only had stud at the edge of each wall. So we ran a piece of wood across the wall and then mounted the rail to the wood. don't use the metal legs. They are not very adjustable if everything is a bit unlevel. If you are really worried you could just lay some timber under the cabinet bottoms. or use this https://www.ikea.com/au/en/p/metod-floor-anchoring-frame-f-ktchn-islnd-60557034/ Feet are designed to help level the cabinet not carry the cabinet weight. The cabinet weight is carried down the wall. More on reddit.com

Looks great! 👍 More on reddit.com

The supports (metal pegs/L brackets) are included with the Utrusta shelves. If they have already been unwrapped then hopefully the installers left them in a bag somewhere. More on reddit.com