Hmm I dont seem to have any drift issues with mine. I find it very precise and predictable.
I don't think you understand the issue.
All drawn using my Xai, the top with 0 prediction, the bottom has those settings maxed out, each line drawn as fast as possible.
Each sensor with prediction can have varying degrees of it, and I don't remember the MX518 being as bad as that worst case scenario on the bottom, but I know it has it, I'll have to dig it out of storage to test it properly.
All I know is that I hate it, when I'm making a fine tuned adjustments while playing with a mouse that has prediction I often feel like I'm wrestling with the mouse to get it to do what I want to which can be a very unwelcome hindrance (note the diagonal lines on the bottom set converge as the sensor forces it as it thinks I might be trying to draw a curve when I don't want it).
Not to mention all the buttons are configurable for whatever keystroke you want. I assign the sensitivity buttons to other uses.
While that is true, its still archaic in the sense that just about any other modern gaming mouse has programmable firmware or internal memory for storing changed settings, whereas the MX518
requires the software to be installed in order for it to be reprogrammed and remain functional as such. For instance I can set up my G9x or Xai any way I want and then plug it into any computer I want and it will work as I want it to without installing any software to configure it.
If you liked the copperhead I would go for an MX518.
They're two completely different forms. I know the MX500 shape and weight is more conducive to a finger grip than most right hand palm oriented mice are but its definitely not in the same class as the Copperhead.
I hate all laser mice. The lasers are too strong so if I have to pick up the mouse, the laser will still track. That's why I bought an MX518.
You've tried all lasers to know you hate them all?
IME the mice with the worst reputations for lift off distance are the older LED Opticals, certainly not the newer lasers, however just about all my dozen+ mice have identical lift off distances on any of my mousing surfaces (all of them dark, all of them hard ie glass/plastic/aluminum)