FWIW I used similar IKEA units.

Cheap and flexible, although the way they work is different (uprights have holes drilled every 2cm or so for their entire length, and you insert metal dowels at the height you need and the shelves clip into that.

What sold it for me was that the IKEA ones are made of wood, so it makes it trivially easy to modify - cut a bit out here, screw something in there etc. This made it ideal for my shed workshop build where I needed some customisations for awkward tools and I could put a workbench exactly where I want it just by screwing it in. Finally just screw the uprights together and into the wooden walls of the shed and you have a rock-solid custom-built racking system that can be reconfigured and modified easily.