The issue with Hybrids is the connection. Between any two electrically connected components if there is a gap but it's still close enough to make an electrical transfer you get that arcing. Now, if that arc happens between your atty and a 510 pin, it's not really a big concern as both of those are decently solid pieces of metal, it's still not ideal but it's not going to cause any major damage. The top cap of a battery though is pretty weak metal, so a single arch could cause "boom" inducing damage.
So one instance of a bad connection can mean time new batteries or worse. Is it something overly concerning as long as you know what to look for and do regular maintenance, not at all. But, if you're lazy it's just one additional concern that you don't need to have. It's supposed to be less voltage drop, but I don't feel it's worthwhile personally.