Question 1

Are these the ones with non-upgradable firmware and bad chipsets, or were these refurbished with the newer internals that can upgrade the firmware?

Accepted Answer

It does tell me that the device does not support firmware updates.   I am on firmware version.  U77.00_B0012.

I have had mine for about 1 year and have not been disappointed.  I have not had any problem using or updating the logitech software itself.    Great buy for a gaming mouse.

Question 2

Is this a left-handed G600??
I've been looking for one.
The orientation and view of the mouse in all the pictures says it is.
ie, panel of thumb-buttons requires use of the left-hand's thumb.

Accepted Answer

Hello,

Thank you for contacting us in regards to your question.

No this is a right handed G600.

Thank you and have a nice day! 
Newegg Support

Questions & Answers