SteelSeries Rival 600
Inconvenienced
Owned for 3 years, used Daily
Stress Points- Issue #1: silicon grips
The silicon side grips are glued using poor agent: after about a year, they'll start moving around causing inconveniences in grip. The good thing is that this is a warranty case, but any replacement would suffer the same issue, so I would advice removing the original glue and gluing it back using epoxy.
Issue #2: lift-off sensor
The high precision of the sensor is its downside as well: even if your surface seems perfectly flat, it would register lift-offs here and there with the minimum lift-off distance set.
Issue #3: side-button design
The size and placement of the side buttons make them not very convenient to use except the middle button: the back button requires the thumb to be moved back significantly, and the front button is not reachable from the default grip position, so you need to shift your whole palm a bit forward to click the button. 
Positive Remarks- If you glue the side grips using a proper agent, adjust the lift-off distance to avoid false positive lift-offs, and ignore the side buttons, this is the most reliable mouse out of those I had experience with (Razer Mamba TE, Logitech G502, and Logitech G903).
- Would you buy it again?
No