It may not be "luck." Especially with coils, flooding, etc. It may actually be "technique." Some people feel they are "unlucky" with vaping equipment when sometimes, it requires a certain amount of research/figuring things out and etc. I'm not pointing to you specifically, and I agree that Smok can sometimes be hit or miss, but with some of these tanks and coils, it's really important to try and resolve issues, not necessarily blame the manufacturer.
I think
@OlderNDirt says it more eloquently than I, but because Smok is such a common brand, there are times where someone complains of an issue but doesn't necessarily do the research (or at least doesn't report back once they are successful) when someone with more experience with the device is able to "resolve" said luck/issue.
If a mod arrives DOA, that's bad luck. Flooding, etc.... Well, I had a lot of that at the start while learning to use an RTA. I didn't consider myself unlucky, I considered myself unskilled/unpracticed. And yet, I just set up my newest RTA in under 20 minutes today. At the beginning it might take several hours and many, many modifications to my "technique." So if you consider yourself unlucky, it might be more fruitful to consider what you can do to resolve an issue, not just move on to another tank/manufacturer. I do think some manufacturers may be trickier than others... I can't set up a doggystyle RTA to save my life for example. I am "bad" at that RTA, that RTA is not "bad."
Anna