Soft weights to conform but they can also get caught up making installation a bit tougher. They aslo loose the coating off the beads and deteriorate faster because the lead then has greater exposed surface area. Coated lead weights last the longest but because of the coating may be tighter in a pocket. I’ve found that many of the rear BC pockets that are rated for 5 lbs do not fit soft or coated lead weights only the solid version which it seems barely allow the weight to slip in and flaps to lock down. Even the side pockets of many BCD function better with hard uncoated lead weight for the first to slide in as they dont tend to get caught and guide the second weight whether it is solid or soft. When used i a pouched belt soft aids comfort as it may in the BCD overall hard uncoated weights are the most reliable for function and probably will outlast the soft weight. I own and use a mix of hard and soft but when using my dive requires maxing out the rear pockets it’s hard weight and if I need more them 10 lbs between the dumpable side pockets the first weight will be hard. When I dive my Backplate & wing wet I use all soft and with the BP&W using drysuit is the only time I use coated hard weight in the way of 2) 5lb weights on the belt with a pocket in between them that can hold another 10 lbs which I prefer as softweight. So the answer to your question is it is highly subjective to your configuration.