Rodent recommendations?

[Aergan]

My former vermin (Logitech M555b) has squeaked its last I'm afraid.

 

The deceased:

 

 

I'm currently using a very worn Logitech NX80 which was kind of a precursor to the M555b:

 

 

I'm looking for a suitable replacement please in the <= ?45 bracket?

 

I'm after something symmetrical, wireless (propriety or Bluetooth), decent build quality, preferably with a middle mouse button and not too large (as I have quite stubby fingers). The NX80 (above) is very prone to signal issues as it's an early 2.4Ghz design, no Unify etc. so it's not something I plan to keep using longer than I have to.

 

I've tried a Logitech M557 (successor to the M555b) but found it to be far to light and shares too many similar design characteristics (and likely flaws too).

 

Advice is much appreciated.

[Mindovermaster Moderator]

I'm using several different kinds of mice, M305, M315, as well as M235. I find them quite nice.