BIG WARNING on using L-Nav as your gear warning system.
You only have one volume knob and it controls volume for ALL functions, en mass.
If you like to turn down the volume of your vario when entering the pattern to land, you will be turning down the volume of your gear warning alarm also.

Major strong point of newer systems, like the S80, is that volume adjustment is distinct for each alarm or audio function. Thus, if you turn down the volume of the vario when entering the pattern the volume of the gear warning will not be affected.