I'm handy but had never installed cabinets until now. We fired our terracotta tiles ourselves and the tiles are very thick and the grout lines are pretty deep and wide. So leveling on a more traditional surface like that was definitely a concern. I also got a lot of good email feedback in advance about my island layout and having that level of responsiveness is super. I did place multiple orders because we modified our layout a few times and rearranged cabinets for width needs. All the orders arrived quickly and completely. Installing the levellers on the cabinets is easy - the biggest task was really dealing with the plastic brackets holding the toekicks on, which all had to be pried out, then the toekicks nailed back on before drilling. I borrowed a laser level, but it wasn't really necessary for my short runs except to keep both sides of the dishwasher gap the same height. I had someone help check the level above either with the laser or the level while I adjusted the screws at the bottom. It was super easy to just adjust them perfectly in no time. The cabinets now have countertops and only the island remains to be done in the kitchen, but we have other cabinet bases still to use elsewhere in the house, and I expect to be buying a few more. I would definitely use these levelers again on other projects in the house. I can't imagine having to deal with shims. Making this one really awkward task seem insignificant to the whole cabinet project says a lot about the product's value. Everything to do with the leveling was truly frustration-free.