I splashed out on some allen keys a few years ago. Whilst the tools themselves are great, the holder (like many of the above) is a bit annoying.
If you have to remove a larger tool to get at a smaller one it just gets annoying… and there should be no getting annoyed with good tools. Sure you could forgo the holder and put them somewhere else, but then you soon find yourself wondering where you put one. Also not good.
When you’re at that critical moment working on something and you’ve got your hands full and you suddenly realise you need another smaller allen key. If you can’t easily get hold of it then your posh tools are at risk of being useless.
A lot of waffling and no real input other than make sure the holder of your good allen keys is also good.