No issues with retention. They lock on and stay on. The packout system is rather nice, expensive but nice. I haven't found a small parts sorting system that I like more than these. Sortimo is nicer, but even more $ than packout. There is a ton of aftermarket 3d printed customization for...
My favorites have always been the Oldaker leads. The points are very sharp, and they use screw on accessories. The hook style end clips are essential accessories IMO.
I get them from the local electronics supply, but it looks like their website is at usprobes.net
This is great. I've been thinking about picking up one of these recently and hadn't thought about the points you make. I was gravitating towards the fuel before I saw this but now I think I'll change my mind and go with the non fuel version.