If I recall correctly, I've bothered with precisely four designs created by others to date. One is an AMS button enhancer, the second is a really smart set of AMS desiccant bin designs (after I'd designed and printed my own), the third is a simple two piece AMS HT riser and the fourth is a CZ 600 bolt disassembly tool. The last one I actually recreated to clean up some artifacts, remove an unneeded feature and add some inlay text (as a test), but I copied the thing otherwise (and it works really damn well).
Typically it's faster for me to just make what I want/need than deal with hunting down and potentially needing to modify something someone else created. Granted, I do have the advantage of software access, professional training as well as a few decades of designing all manner of things.
Easier than it's ever been and more accessible to the average Joe than ever before. As someone who promotes investing in one's self through the learning of new skills, I highly recommend getting into CAD (for many reasons). I even recommend starting with a bit of 2D CAD before trying 3D modeling of any kind. In most CAD software, understanding the 2D tools and working in 2D planes is critical for developing 3D models, be they surface or solid.
