tbh other peoples' opinions of mice are going to be completely subjective and based on their experience. It won't work for you. My recommendation is, if you play at that high of a level, is buy an MX518 to use so you're not completely handicapped and then buy additional mice to test out during farm/off-raid nights to see if you like any other mice, and then return the MX518 for a refund if you find something better.
From personal experience, gaming mice and keyboards are entirely overrated. I struggle a lot with total number of available keybinds becasue I'm lefthanded, and instead of using 'wasd' for movement, I use 'ijkl'. This prevents me from being able to use the ctrl key as a modifier entirely and limits my modifier macros to 2/3 of what a typical player might play with. The reason I say this, is because being left-handed means i use my mouse in my left hand, and most of the gaming mice are not ergonomically shaped for left handed people so I can't use them at all. The ones that are properly shaped have the macro buttons on the left-inside part of the mouse for a right-handed persons thumb, but that would be my pinky, so it doesn't work. I've tried, over the years, a few of the symmetrical mice that aren't form-factored by handedness and have just found that the adjustment of going from a standard mouse to a precision gaming mouse has been way too much sensitivity to relearn and I ended up just going back to whatever I was using. I did, however, recently purchase a Logitech G300, and it's perfect for me because it's symmetrical, has symmetrical buttons on both the top-left and top-right of the mouse (only two on each side, not 12 like some other ones have) but it's allowed me to bind ctrl to one of those buttons and give me a whole slew of new keybinds to use. It's also not really all that much more sensitive than a standard laser mouse, which I like. All said and done I perform just as well as anyone with a gaming mouse and crazy kebyind setups, I just have a little less flexibility in my binds.
But really, my experience is probably not the same as anyone elses, nor will anyone elses be the same as yours. I suggest just buying a new one and trying out other kinds of mice if you have enough disposable income to afford it. If not, well, you know how the saying goes "if it ain't broke..."