I have used this particular Logitech mouse for several years now. Recently, bought another one to go with a keyboard I also recently bought. The first one I bought about four years ago still works well and the long-term reliability of it is good.
I bought this because of the unifying receiver to connect with a keyboard I got from a reuse forum. It worked perfectly!
The mouse M525 and the keyboard K520 both connected and I am satisfied.
The mouse is quite comfortable. Slightly bigger than my Microsoft 3500 mouse, I think that is an advantage for me even my average hand.