I'm in exactly the same boat as you vulkan, which is why I don't do stacks!
The few I have tried are mostly mush.
You really need a focus rail like a manfrotto 454, so you can move the focal plane in one direction only.
Perhaps after a couple of years practise doing it handheld I might get closer to the likes of LordV.
Thing is, I'd rather not produce botched handheld stacks - it's too hit or miss for me at the moment - so I'm concentrating on single shots and maximising the subject focus coverage. That's challenging enough!
